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###### Environmental Protection Agency

          - 40 CFR Part 52 
          - [R10-OAR-2004-WA-0001; FRL-7866-6] 

# AGENCY:

Environmental Protection Agency (EPA). 

# ACTION:

Proposed rule. 

# SUMMARY:

                        EPA is proposing to approve Washington's State Implementation Plan for the Wallula, Washington serious nonattainment area for particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers (PM10). Initially Wallula was classified as a moderate nonattainment area for PM10                         pursuant to the Clean Air Act Amendments of 1990. In 2001, it was reclassified as a serious nonattainment area for PM10. As a result, Washington was required to submit a serious area plan for bringing the area into attainment. This action                               ( print page 5086)                            proposes to approve the Wallula serious area plan dated November 15, 2004 and submitted to EPA on November 30, 2004.                     

# DATES:

Comments must be received on or before March 3, 2005. 

# ADDRESSES:

Submit your comments, identified by Docket ID No. R10-OAR-2004-WA-0001, by one of the following methods: 

                        1.                         *Federal eRulemaking Portal: http://www.regulations.gov.*                         Follow the on-line instructions for submitting comments.                     

                        2.                         *Agency Web Site: http://www.epa.gov/​edocket.*                         EDOCKET, EPA's electronic public docket and comment system, is EPA's preferred method for receiving comments. Follow the on-line instructions for submitting comments.                     

                        3.                         *E-mail: r10.aircom@epa.gov.*

                        4.                         *Mail:*                         Office of Air Quality, Attn: Environmental Protection Agency, Attn: Donna Deneen, Mailcode: OAQ-107, 1200 Sixth Avenue, Seattle, WA 98101.                     

                        5.                         *Hand Delivery:*                         Environmental Protection Agency Region 10, Attn: Donna Deneen (AWT-107), 1200 Sixth Ave., Seattle, WA 98101, 9th floor. Such deliveries are only accepted during EPA's normal hours of operation, and special arrangements should be made for deliveries of boxed information.                     

*Instructions:*                         Direct your comments to Docket ID No. R10-OAR-2004-WA-0001. EPA's policy is that all comments received will be included in the public docket without change, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through regulations.gov or e-mail. The EPA EDOCKET and the Federal regulations.gov Web site are an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an e-mail comment directly to EPA without going through EDOCKET or regulations.gov, your e-mail address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses.                     

*Docket:*                         All documents in the docket are listed in the EDOCKET index at                         *http://www.epa.gov/​edocket.*                         Although listed in the index, some information may not be publicly available, such as CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically in EDOCKET or in hard copy at EPA Region 10, Office of Air Quality, 1200 Sixth Avenue, Seattle, Washington, from 8 a.m. to 4:30 p.m. Monday through Friday, excluding legal holidays. Please contact the individual listed in the                         **FOR FURTHER INFORMATION CONTACT**                         section to schedule your inspection.                     

# FOR FURTHER INFORMATION CONTACT:

                        Donna Deneen, Office of Air Quality, Region 10, AWT-107, Environmental Protection Agency, 1200 Sixth Ave., Seattle, WA 98101; phone: (206) 553-6706; fax number: (206) 553-0110; e-mail address:                         *deneen.donna@epa.gov.*

# SUPPLEMENTARY INFORMATION:

 

## Table of Contents 

I. What Action Are We Taking? 

II. What Is the Background for This Action? 

                        A. Description of the Wallula PM10                         Serious Nonattainment Area                     

B. Nonattainment History of Wallula 

C. Wallula Monitoring Network 

                        D. Monitored PM10                         Air Quality in the Wallula Nonattainment Area                     

III. What Are the Clean Air Act's Planning Requirements for Serious Nonattainment Areas? 

A. Moderate Area Requirements Under Section 189(a) 

B. Serious Area Requirements Under Section 189(b) 

IV. How Does the Wallula Serious Area Plan Meet Clean Air Act Planning Requirements? 

A. Plan Overview 

B. Emissions Inventory 

C. Implementation of Best Available Control Measures 

D. Major Source Definition 

E. Attainment Demonstration 

                        F. Implementation of Best Available Control Measures on Major Stationary Sources of PM10                         Precursors                     

G. Contingency Measures 

H. Reasonable Further Progress (RFP) and Quantitative Milestones 

I. Transportation Conformity 

## I. What Action Are We Taking? 

                    On November 30, 2004, the State of Washington, Department of Ecology (Ecology) submitted a State Implementation Plan revision entitled “A Plan for Attaining Particulate Matter (PM10) Ambient Air Quality Standards in the Wallula Serious Nonattainment Area” (Wallula serious area plan or Plan). This plan was submitted to meet Clean Air Act (CAA or Act) planning requirements for a PM10                     serious nonattainment area. We have completed a review of the technical and administrative adequacy of this plan and presented the results in a Technical Support Document (TSD). The TSD provides the basis for our approval of the plan and discusses in more detail the air quality planning requirements for serious and moderate PM10                     nonattainment areas in subparts 1 and 4 of title I of the CAA. We are proposing to approve the Wallula serious area plan based on a determination that the plan complies with the CAA requirements for serious PM10                     nonattainment area plans.                 

This preamble describes our proposed action on the Wallula serious area plan and provides a summary of our evaluation of the Plan. 

## II. What Is the Background for This Action? 

###                     A. Description of the Wallula PM10                     Serious Nonattainment Area                 

The Wallula nonattainment area lies in eastern Washington just north of the Oregon border in the southern portion of the Columbia Plateau. The nonattainment area includes parts of Walla Walla and Benton Counties and a small portion of Sacajawea State Park in Franklin County. 

                    The Wallula area is located in the lowest and driest section of eastern Washington, receiving as little as seven to nine inches of precipitation each year. Summer precipitation is usually associated with thunderstorms and it is not unusual for four to six weeks to pass without measurable rainfall in the summer. The Columbia Plateau is also known for prolonged periods of strong winds which carry dust particles for hundreds of miles downwind. Wind erosion is a particular problem in the area because of the natural dustiness of the region due to its dry environments, scant vegetation, unpredictable high winds, and soils which contain substantial quantities of PM10. See “Farming with the Wind: Best Management practices for Controlling Wind Erosion and Air Quality on Columbia Plateau Croplands” (1998).                 

                    The Wallula nonattainment area is generally rural and agricultural. Prominent land uses include dryland and irrigated cropland, industrial sites and natural vegetation. There is only one major stationary source in the                           ( print page 5087)                        nonattainment area, a large pulp and paper mill and its associated compost facility and landfill. There is also a large beef cattle feedlot, a beef processing plant, a natural gas compressor station, grain storage silos and a few other minor sources. The population of the area is approximately 4800. Two-thirds of the population live in the northwest portion of the nonattainment area in the unincorporated town of Burbank.                 

## B. Nonattainment History of Wallula 

                    The Wallula area was designated nonattainment for PM10                     and classified as moderate under sections 107(d)(4)(B) and 188(a) of the CAA upon enactment of the Clean Air Act Amendments of 1990.[1] *See*40 CFR 81.348 (PM10                     Initial Nonattainment Areas);                     *see also*56 FR 56694 (November 6, 1991). Under subsections 188(a) and (c)(1) of the CAA, all initial moderate PM10                     nonattainment areas had the same applicable attainment date of December 31, 1994.                 

                    States containing initial moderate PM10                     nonattainment areas were required to develop and submit to EPA by November 15, 1991, a state implementation plan (SIP) revision providing for, among other things, implementation of reasonably available control measures (RACM), including reasonably available control technology (RACT), and a demonstration of attainment of the PM10                     NAAQS by December 31, 1994.                     *See*                     section 189(a) of the CAA.[2]                                          In response to this submission requirement, Ecology submitted a SIP revision for Wallula on November 15, 1991. Subsequently, Ecology submitted additional information indicating that nonanthropogenic sources may be significant in the Wallula nonattainment area during windblown dust events. Based on our review of the State's submissions, we deferred action on several elements in the Wallula SIP, approved the control measures in the SIP as meeting RACM/RACT, and, under section 188(f) of the CAA, granted a temporary waiver to extend the attainment date for Wallula to December 31, 1997.                     *See*60 FR 63109 (December 6, 1995)(proposed action); 62 FR 3800 (January 27, 1997) (final action). The temporary waiver was intended to provide Ecology time to evaluate further the Wallula nonattainment area and to determine the significance of the anthropogenic and nonanthropogenic sources impacting the area. Once these activities were complete or the temporary waiver expired, EPA was to make a decision on whether the area was eligible for a permanent waiver under section 188(f) of the CAA or whether the area had attained the standard by the extended attainment date.                     *See*                     62 FR at 3802.                 

                    On February 9, 2001, EPA published a                     **Federal Register**                     notice making a final determination that the Wallula area had not attained the PM10                     standard by the attainment date of December 31, 1997.                     *See*66 FR 9663 (February 9, 2001) (final action); (65 FR 69275 (November 16, 2000) (proposed action). EPA made this determination based on air quality data for calendar years 1995, 1996, and 1997. As a result of that finding, the Wallula PM10                     nonattainment area was reclassified by operation of law as a serious PM10                     nonattainment area effective March 12, 2001 with an attainment date of December 31, 2001.                     *See*                     188(b)(2)(A) and 188(c)(2). On October 22, 2002, EPA found that the Wallula nonattainment area attained the NAAQS for PM10                     as of December 31, 2001. EPA's finding was based on EPA's review of monitored air quality data reported for the years 1999 through 2001. EPA's finding included a determination that exceedances that occurred in the area on June 21, 1997, July 10, 1998, June 23, 1999, and August 10, 2000 were due to high winds and, consistent with EPA policy, not considered in determining the area's air quality status.                     *See*                     Memorandum from EPA's Assistant Administrator for Air and Radiation to EPA Regional Air Directors entitled “Areas Affected by Natural Events,” dated May 30, 1996 (EPA's Natural Events Policy). EPA has stated that it will treat ambient PM10                     exceedances caused by dust raised by unusually high winds as due to uncontrollable natural events (and thus excludable from attainment determinations) if either (1) the dust originated from nonanthropogenic sources or (2) the dust originated from anthropogenic sources controlled with best available control measures (BACM).                     *See*                     EPA's Natural Events Policy, pp. 4-5.                 

After EPA made its finding of attainment, Ecology continued to investigate the one remaining exceedance on July 3, 1997 that led to the area's reclassification to serious. Meteorological information indicated that this exceedance was not due to high winds. Ecology concluded that the exceedance was likely attributable to a one time non-recurring activity involving the transportation of 130 truckloads of finished compost near the monitor on July 1-3, 1997. Although this activity was non recurring and EPA subsequently determined that the area attained the standards as of December 31, 2001, the Wallula area remains classified as a serious nonattainment area. As a result, a second nonattainment serious SIP revision—in addition to the moderate area SIP revision required under section 189(a)— is required under section 189(b). 

## C. Wallula Monitoring Network 

For most of the period since 1986, Ecology's monitoring network for the Wallula nonattainment area has consisted of a single monitoring site. This site is referred to in EPA's Air Quality System (AQS) database as the Nedrow Farm/Wallula Junction monitoring site (site id no: 53-071-1001). This monitoring site was discontinued pursuant to an agreement with the landowner to stop using the monitoring location by October 31, 2003. 

                    In anticipation of the closure of the Nedrow Farm/Wallula Junction monitoring site, Ecology provided EPA Region 10 with an analysis of the two potential replacement sites and a recommendation of Burbank for the replacement site on the grounds that the monitor at the Burbank site measured the same air mass as the Wallula monitoring site. Based on EPA's determination that there was a strong correlation in data measured at the two sites, EPA agreed that the Burbank monitor was an appropriate replacement site to the original Wallula monitoring site. Ecology discontinued the Wallula Port monitoring site in April 2004. The Burbank monitor is now the sole PM10                     monitoring location in the nonattainment area, with a sampling frequency of once every three days.                 

###                     D. Monitored PM*10*                     Air Quality in the Wallula Nonattainment Area                 

                    There are two separate NAAQS for PM10: an annual standard of 50 ug/m3 and a 24-hour standard of 150 ug/m3. The area has never violated the annual PM10                     NAAQS but it has violated the 24-hour PM10                     NAAQS. Currently the area is in compliance with both PM10                     NAAQS. A thorough discussion of the area's compliance with the 24-hour PM10                     standard as of December 31, 2001 is contained in EPA's attainment determination.                     *See*                     67 FR at 64816. In short, the area had one exceedance that resulted in a violation of the 24-hour PM10                     NAAQS in 1997. All other exceedances that occurred from 1995 through 2001 were determined to be due                           ( print page 5088)                        to uncontrollable high wind natural events and, consistent with EPA's Natural Events Policy, not considered in determining the air quality status of the area.                 

                    Since December 31, 2001, additional exceedances of the 24-hour standard have occurred on September 29, 2002, October 30, 2003, November 11, 2003, and April 27, 2004. All were flagged by Ecology as due to high wind events under EPA's Natural Events Policy. Based on the information provided by Ecology about these events, other information provided by Ecology regarding control measures being implemented at the time of the events, and the area's soil and climate characteristics, we conclude that the exceedances that occurred on September 29, 2002, October 30, 2003, November 11, 2003, and April 27, 2004 were due to high wind natural events and that, on those dates, anthropogenic sources contributing to the exceedances were controlled with Best Available Control Measures. Therefore, EPA proposes to exclude the exceedances on all four dates from consideration in determining whether the Wallula PM10                     nonattainment area is currently attaining the standards. Excluding these exceedances, the Wallula PM10                     nonattainment area is attaining both the 24-hour and annual average PM10                     NAAQS.                 

## III. What are the Clean Air Act's Planning Requirements for Serious Nonattainment Areas? 

                    Wallula is a PM10                     nonattainment area that was reclassified to serious because it failed to attain the 24-hour PM10                     NAAQS by the moderate area attainment date of December 31, 1997. Such an area must submit revisions to its implementation plan that address requirements for serious PM10                     nonattainment areas under CAA section 189(b). In addition, the area must satisfy requirements for initial moderate PM10                     nonattainment areas under section 189(a).                 

### A. Moderate Area Requirements Under Section 189(a) 

                    Under section 189(b)(1) of the CAA, the Wallula serious area plan must meet requirements for a moderate area plan in addition to requirements for a serious area plan. EPA approved some but not all of the SIP revision Ecology submitted initially on November 15, 1991 to meet these moderate area planning requirements.                     *See*62 FR 3800 (January 27, 1997). The approved elements included those pertaining to RACM, the monitoring network, consultation and public notification, provisions for revising the plan, prohibiting sources from impacting other states, adequacy of personnel, funding and authority, enforceability of control measures, and the control of precursors. In addition, EPA approved a permitting program for the permitting of new major sources in nonattainment areas.                     *See*60 FR 28726 (June 2, 1995). EPA has not previously approved the emissions inventory, the attainment demonstration, contingency measures, and quantitative milestones. These remaining requirements must be met for both an approvable moderate and serious area plan. EPA believes all of the remaining requirements for a moderate area plan are covered by the serious area plan requirements, which are discussed more fully below.                 

### B. Serious Area Requirements Under Section 189(b) 

                    The Wallula nonattainment areas is required to meet the following requirements that apply to serious PM10                     nonattainment areas:                 
    - A comprehensive, accurate, and current inventory of actual emissions from all sources of PM 10                      (CAA section 172(c)(3)).                 
    - A demonstration (including air quality modeling) that the plan will provide for attainment as expeditiously as practicable by no later than December 31, 2001 or, where the State is seeking an extension of the attainment date under section 188(e), a demonstration that attainment by December 31, 2001 is impracticable and that the plan provides for attainment by the most expeditious alternative date practicable (CAA sections 188(c)(2) and 189(b)(1)(A)).
    - Assurances that the BACM, including best available control technology (BACT) for stationary sources, for the control of PM 10                      shall be implemented no later than 4 years after the area is reclassified (CAA section 189(b)(1)(B)).                 
    - A requirement, under section 189(b)(3) , that the terms “major source” and “major stationary source,” used in implementing a new source permitting program under section 173 and control of PM 10                      precursors under section 189(e), include any stationary source or group of stationary sources located within a contiguous area and under common control that emits, or has the potential to emit, at least 70 tons per year of PM 10 .                 
    - Assurances that BACT on major stationary sources of PM 10                      precursors shall be implemented no later than 4 years after the area is reclassified except where EPA has determined that such sources do not contribute significantly to exceedences of the PM 10                      standards (CAA section 189(e)).                 
    - Quantitative milestones which are to be achieved every 3 years and which demonstrate reasonable further progress (RFP) toward attainment by the applicable attainment date (CAA sections 172(c)(2) and 189(c)).
    - Contingency measures to be implemented if the area fails to make RFP or attain by its attainment deadline. These contingency measures are to take effect without further action by the State or EPA. CAA section 172(c)(9).

                    Furthermore, PM10                     serious area plans must meet the general requirements applicable to all SIPs including reasonable notice and public hearing under section 110(l), necessary assurances that the implementing agencies have adequate personnel, funding and authority under section 110(a)(2)(E)(i) and 40 CFR 51.280, and a description of enforcement methods as required by 40 CFR 51.111.                 

                    We have issued a General Preamble [3]                                          and Addendum to the General Preamble [4]                                          describing our preliminary views on how EPA intends to review SIPs submitted to meet the CAA's requirements for PM10                     plans. The General Preamble mainly addresses the requirements for moderate areas and the Addendum, the requirements for serious areas.                 

## IV. How Does the Wallula Serious Area Plan Meet Clean Air Act Planning Requirements? 

### A. Plan Overview 

                    The Wallula serious area plan describes the efforts to determine the cause of PM10                     exceedances in Wallula and concludes that all of the PM10                     exceedances have been due to fugitive dust. Analysis of the filters from the PM10                     monitors, on high and low wind days and when high and low levels of PM10                     are recorded, reveals that dust is the primary material on the monitors. The emissions inventory identifies agricultural dust as the predominant source of PM10                     emissions in the area.                 

                    Ecology has presented information showing that all but one of the exceedances since January 1, 1995 were caused by dust due to unusually high winds and that, to the extent the dust was attributable to anthropogenic (man-made) sources, such sources are                           ( print page 5089)                        controlled with best available control measures. As discussed above, EPA agrees with the information presented by Ecology with respect to these exceedances and therefore believes such exceedances are appropriately excluded in determining whether the area is attaining the PM10                     standards.                 

                    As also discussed above, meteorological information indicated that the exceedance that occurred on July 3, 1997 was not due to high winds. In its investigation Ecology determined that dust was the predominant material found on the monitor that day. After analyzing the PM10                     filter, the meteorology, the results of dispersion modeling, the emissions inventory, and chemical mass balance modeling for that day, as well as for other days, Ecology concluded that the most likely primary cause of the exceedance was dust raised by the transport of 130 truck loads of compost on unpaved roads from the compost facility to a nearby fiber farm from July 1-3, 1997, an unusual and nonrecurring activity.                 

                    The Wallula serious area plan demonstrates attainment with the PM10                     standards by showing that agricultural activities in the area are employing best management practices to reduce PM10                     emissions, and that the feedlot, compost facility and other sources of fugitive PM10                     emissions are employing best available control measures. This includes measures to ensure the fugitive dust impacts of unusual or extraordinary activities are considered and minimized so as to prevent a recurrence of the type of exceedance that occurred on July 3, 1997.                 

                    The following sections present a discussion of how the Wallula serious area plan meets the CAA requirements for serious PM10                     nonattainment areas.                 

### B. Emissions Inventory 

                    CAA section 172(c)(3) of the CAA requires that nonattainment area plans include a comprehensive, accurate, and current inventory of actual emissions from all sources in the nonattainment area in the designated base year and a future attainment year. Ecology chose 1997 as the base year because the area's redesignation to serious was based on a recorded exceedance of the 24-hour PM10                     standard that occurred in 1997. The inventory focused on emissions for a typical day during the summer, the time of year when PM10                     emissions tend to be highest. Ecology excluded emissions associated with the recorded exceedance on July 3, 1997 (involving the one-time transport of 130 truckloads of finished compost near the monitor) because those emissions were the result of a nonrecurring activity and therefore not appropriately included in a baseline inventory. It also excluded anthropogenic and nonanthropogenic emissions associated with high wind days because the exceedances associated with such events are addressed under EPA's Natural Events Policy and Ecology's Natural Events Action Plan. The 1997 baseline emissions inventory represents not only baseline emissions but current emissions as well. This is because the nature of the emissions and the small number of sources in this rural, agricultural nonattainment area have changed little since 1997.                 

                    Based on our review of the Wallula serious area plan, we believe that the emissions estimates for all of the identified sources and source categories are based on emissions factors and methodologies recommended by EPA, or are derived from a specific study or data collected from a source category in the area (                    *e.g.*                    , vacant lots). We therefore propose to find that the methodologies and calculations used by Ecology to develop the emissions inventory rely upon reasonable assumptions and provide a sufficient basis upon which to assess the impact of control measures on future PM10                     emissions in the Wallula area. EPA is therefore proposing to approve the emissions inventory in the Wallula serious area plan as meeting the requirements of CAA section 172(c)(3).                 

### C. Implementation of Best Available Control Measures 

                    CAA section 189(b)(1)(B) requires that a PM10                     serious area plan provide for the implementation of BACM within four years of reclassification to serious. The CAA does not define what level of control constitutes a BACM-level of control. In guidance, we have defined it to be, among other things, the maximum degree of emission reduction achievable from a source or source category which is determined on a case-by-case basis, considering energy, economic and environmental impacts. Addendum at 42010.                 

                    Under our applicable guidance, BACM is applied to each significant (i.e., non-de minimis) source category. EPA has established a presumption that a “significant” source category is one that contributes 5 ug/m3                     or more of PM10                     to a location of 24-hour violation and 1 ug/m3                     or more for the annual standard. Addendum at 42011. EPA follows a four-step process for evaluating BACM in PM10                     serious area plans. Addendum at 42010-42014. The steps are:                 

                    1. Develop a detailed emissions inventory of PM10                     sources and source categories;                 

                    2. Model to evaluate the impact on PM10                     concentrations over the standards of the various sources and source categories to determine which are significant;                 

3. Identify potential BACM for significant source categories and evaluate their reasonableness, considering technological feasibility, costs, and energy and environmental impacts; and 

4. Provide for the implementation of the BACM or provide a reasoned justification for rejecting any potential BACM. 

                    When the process is complete, the individual measures should then be converted into a legally enforceable vehicle (                    *e.g.*, a regulation or permit process). CAA sections 172(6) and 110(a)(2)(A). Also, the regulations or other measures should meet EPA's criteria regarding the enforceability of SIPs and SIP revisions. General Preamble at 13541.                 

                    The development of the emissions inventory is discussed in the preceding section. EPA believes that the base-year emissions inventory contains a sufficient level of detail to enable appropriate evaluation of the control measures for BACM purposes in the Wallula serious area plan. Using a combination of chemical analysis, source apportionment, and its base emissions inventory, the plan identifies the following source categories as being significant contributors to violations of the 24-hour PM10                     standard in the Wallula area: [5] 

1. Agricultural tilling. 

2. Boise Paper Solutions—Composting Facility and Landfill. 

3. Unpaved road dust. 

4. Tyson Fresh Meats (formerly IBP, Inc.), a beef processing facility. 

5. Simplot Feeders Limited Partnership, a beef cattle feedlot (Simplot feedlot). 

                    Based on EPA's review of the modeling and other analyses described in the plan, we believe Ecology appropriately evaluated the impact of various PM10                     sources and source categories on PM10                     levels in the area and derived a comprehensive list of significant sources and source categories for the area. Ecology included sources of fugitive emissions, and not sources of combustion, in its list of source categories to be evaluated because no significant contribution from combustion products was detected on sampling filters. The following                           ( print page 5090)                        discussion contains a summary of the results of the BACM analysis for Wallula and the control measures adopted by Ecology.                 

                    1. Agricultural tilling. In finding that the Wallula area attained the 24-hour PM10                     standards by the applicable attainment date of December 31, 2001, EPA determined that sources of agricultural windblown dust in the Wallula area were implementing BACM.                     *See*67 FR 64815 (October 22, 2002). The BACM demonstration for the area relied on best management practices (BMPs) identified in “Farming with the Wind: Best Management Practices for Controlling Wind Erosion and Air Quality on Columbia Plateau Croplands,” (1998), the Columbia Plateau Natural Events Action Plan (1998) (Columbia Plateau NEAP), and data collected by the Natural Resources Conservation Service (NRCS). In the same action, we noted that identification and application of BACM for agricultural lands is evolving and that we expect Ecology to continue efforts in identifying and implementing BACM on sources of agricultural windblown dust in the Wallula area in order for future exceedances caused by high winds to be characterized as “natural events” and excluded in attainment determinations.                 

Since our attainment determination, both “Farming with the Wind” and the Columbia Plateau NEAP have been revised to include updated information on the best management practices, their effectiveness, and special projects being implemented in the area to reduce emissions from agricultural sources. In its 2003 Columbia Plateau NEAP, Ecology defines BACM for agricultural fields to be conservation programs and practices that reduce or minimize wind erosion, and specifically, USDA Conservation Title Programs supplemented by incentive-based implementation of wind-erosion conservation practices or best management practices (BMPs). 2003 Columbia Plateau NEAP, pgs. 18 and 19. In its 2003 annual status report on agricultural BACM implementation, Ecology reports that BMP use has increased in the Columbia Plateau. The document also identifies several ongoing projects specific to the Wallula area to reduce agricultural dust emissions in the Wallula area. This increase in BMPs in the Columbia Plateau, in combination with the ongoing emission reduction projects specific to the Wallula area, indicate an overall upward trend in the widespread use of BMPs in the Wallula area. 

In light of the progress in identifying new BMPs and refining existing ones, better information about their associated effectiveness, a continued upward trend in the widespread use of BMPs, Ecology's commitment in its 2003 Columbia Plateau NEAP to continue activities supporting the increased use of BMPs, and the area's soil and climate characteristics, EPA concludes that the BACM requirement for agricultural sources is being met. Note, however, that identification and application of BACM for agricultural lands is still evolving and we expect Ecology to continue efforts in identifying and implementing BACM on sources of agricultural windblown dust and to revise periodically its Columbia Plateau NEAP, which covers the Wallula area. 

2. Boise Paper Solution—Composting Facility and Landfill. This source category includes emissions from vehicular traffic, windrow turning, materials handling and conveyance, and wind associated with the Boise Paper Solutions composting and landfill. Ecology has issued a title V Air Operating Permit (No. 000369-7) containing a fugitive dust control plan incorporating the measures that were determined as BACM for this facility. The plan requires road watering, rubber drapes on the windrow turning machine, compost row watering, no windrow turning on high wind days, minimization of active face of the landfill, and a prohibition on the placement of materials in the landfill during high wind days. In light of Ecology's evaluation of BACM and its issuance of an Air Operating Permit containing a dust control plan for the facility, EPA concludes that the BACM requirement for this facility is being met. 

                    3. Unpaved roads: Although emissions from unpaved roads contributed only 2.2% to the baseline inventory, quantitative analyses found that dust on the Wallula filters could be attributed to unpaved roads or agricultural fields. Analysis was unable to distinguish between the two sources. Therefore, both unpaved roads and agricultural fields were evaluated for BACM in the Wallula serious area plan. Based on criteria in EPA's                     *Fugitive Dust Background Document and Technical Information Document for Best Available Control Measures*                     (1992), unpaved roads with a length less than 0.5 mile or with less than 20 vehicle trips per day did not receive further consideration for BACM and were not included in the inventory. Ecology put most focus on unpaved roads near the monitor. The focus on these roads recognizes that the truck transport activity associated with the exceedance on July 3, 1997, which led to a violation, took place near the monitor.                

                    Normal traffic on these roads has consisted of staff traveling to service the monitoring site and meteorological station and Ecology staff visiting the monitoring site. The owner of land surrounding these roads has taken steps to limit access to these roads, and the monitoring site has been moved to a site in Burbank, both reducing the amount of travel on the roads. Ecology concluded that no additional controls to reduce PM10                     on unpaved roads in the Wallula nonattainment area are required. Based on Ecology's evaluation and in light of the nature and limited use of unpaved roads in the area, EPA believes that no further controls on unpaved roads are needed to meet BACM requirements.                 

                    4. Tyson Fresh Meats (formerly IBP, Inc.). On December 6, 2002, Ecology issued Administrative Order No. 02AQER-5074 to reduce IBP, Inc.’s potential to emit below the 70 tons per year threshold for major sources in serious PM10                     nonattainment areas. The permit includes hourly and annual limits on throughput and hours of operation to achieve this reduction. In the Order, Ecology determined that the control equipment at IBP constitutes BACT. Based on Ecology's evaluation of BACM/BACT at the facility and the Order limiting the facility's potential to emit, EPA concludes that the BACM/BACT requirement for this facility is being met.                 

                    5. Simplot feedlot. WAC 173-400-040 requires air pollution sources to take “reasonable precautions” to prevent the release of fugitive emissions. To clarify what constitutes “reasonable precautions” for fugitive dust emissions from feedlots, Ecology developed a guidelines document entitled “Fugitive Dust Control Guidelines for Beef Cattle Feedlots and Best Management Practices” (Feedlot Guideline Document). These guidelines are intended to be used in conjunction with WAC 173-400-040 and are implemented through flexible, site-specific fugitive dust control plans developed by each feedlot and approved by Ecology or the appropriate local air authority. Simplot submitted a revised Feedlot Dust Control Plan to Ecology in December 2003. The revised plan reflects the outcome of Ecology's BACM evaluation, which looked at control measures such as increased water application, valve adjustment, addition of sprinklers to improve coverage, irrigation scheduling changes, water trucks to control roadway dust and manure management as potential emissions reduction methods. Ecology                           ( print page 5091)                        approved Simplot's Feedlot Dust Control Plan on December 18, 2003, finding that the plan meets the requirements in the Feedlot Guideline Document and constitutes BACM for this source. Based on Ecology's evaluation of BACM, the Feedlot Guideline Document, the provisions in WAC 173-400-040, and Ecology's approval of Simplot's Feedlot Dust Control Plan, EPA concludes that the BACM requirement for this facility is being met.                 

                    Based on the demonstration of BACM submitted by Ecology for sources in the Wallula area and our discussion above, EPA believes the serious area plan provides for implementation of both RACM and BACM for all source categories that contribute significantly to PM10                     standard violations in the Wallula nonattainment area. EPA therefore proposes to approve the plan as meeting the RACM and BACM requirements.                 

### D. Major Source Definition 

                    CAA section 189(b)(3) requires that the terms “major source” and “major stationary source” used in implementing the major new source permitting program in serious PM10                     nonattainment areas under section 173 and for the control of PM10                     precursors under section 189(e) must include any stationary source or group of stationary sources located within a contiguous area and under common control that emits, or has the potential to emit, at least 70 tons per year of PM10                    . To meet this requirement, Ecology revised the definition of “major stationary source” in WAC 173-400-112. Specifically WAC 173-400-112(1)(b)(i)(A) lowers the PM10                     threshold in nonattainment areas from 100 to 70 tons per year. EPA is proposing to approve this change because it meets the requirements of CAA section 189(b)(3).                 

### E. Attainment Demonstration 

                    CAA section 189(b)(1)(A) requires a demonstration that the area will attain the NAAQS by December 31, 2001. As discussed above, EPA has already determined that the Wallula nonattainment area attained the PM10                     NAAQS by December 31, 2001 (67 FR 64815, November 22, 2002). As discussed below, the Wallula serious area plan provides further documentation in support of that finding.                

                    To demonstrate attainment, Ecology focused on the 24-hour PM10                     exceedance of 210 ug/m3                     that occurred at the Nedrow Farm/Wallula Junction monitor on July 3, 1997. Although there have been other exceedances recorded in Wallula after July 3, 1997, EPA concluded in 2002 that all subsequent exceedances through December 31, 2001, qualified as natural events under EPA's Natural Events Policy. As discussed above and in our finding of attainment, these natural event exceedances are not considered in determining the area's air quality status. Since December 31, 2001, there have been four additional exceedances of the 24-hour PM10                     standard. As also discussed above, however, we are proposing in this notice that these exceedances should also qualify as natural events under EPA's Natural Events Policy. Hence, it is reasonable for Ecology to focus on July 3, 1997 since it is the last time an exceedance not attributed to a natural event has occurred in the area and it is this exceedance that led to the area's reclassification to serious.                 

#### 1. Investigation of the July 3, 1997 Exceedance 

                    To determine the cause of the exceedance on July 3, 1997, Ecology relied on a combination of filter analyses, chemical mass balance modeling, dispersion modeling, and analysis of meteorological and air quality monitoring data. After Ecology's initial analysis, it was not immediately apparent what caused the exceedance. Therefore, Ecology conducted an investigation into whether there were any unusual activities in the area on July 3, 1997, that could have contributed significantly to the measured concentration. This effort led to information that 130 truckloads of finished compost had been transported over unpaved roads near the monitor from July 1-3, 1997. The trucks were loaded at the Boise Paper Solutions-Wallula Mill composting facility and the material was transported over unpaved roads to a fiber farm for use in enhancing cottonwood production. Based on the results of this investigation, Ecology determined that this was an unusual and nonrecurring activity and that it would have resulted in additional PM10                     emissions in the area. This determination, combined with the results of technical analyses, led Ecology to conclude that unpaved road dust caused by truck transport was the primary cause of the July 3, 1997 exceedance. A summary of evidence supporting this conclusion is presented in the TSD.                 

#### 2. Prevention of Future Exceedances 

The transport of finished compost from the compost facility to the fiber farm was a unique event that has not been repeated. The expected benefit for cottonwood production did not materialize and Boise Paper Solutions-Wallula Mill is now putting all finished compost in the compost cell of the landfill at the facility. To ensure that similar events do not occur in the future, Boise Paper Solutions—Wallula Mill developed a dust control plan that is part of its title V air operation permit. The plan covers normal and customary composting operation and also contains a provision specifying that dust effects must be considered in the event of any extraordinary activities outside of normal operations. This provision would have applied to the truck transport of finished compost to the fiber farm on July 1-3, 1997. 

#### 3. Attainment Demonstration 

Based on the information provided by Ecology, EPA believes that Ecology has thoroughly investigated the exceedance on July 3, 1997. EPA further believes that based on the results of the investigation, which included filter analysis, chemical mass balance and dispersion modeling, it is reasonable to conclude that the truck transport of compost on unpaved roads near the monitor caused the exceedance on July 3, 1997. The truck transport activity was a one-time event that is not expected to recur. Other control measures are now in place to prevent both customary and unusual activities from causing a similar exceedance in the future. 

In light of the results of Ecology's investigation, the control measures addressing the July 3, 1997 exceedance, the control measures discussed in section IV.B. above that address air quality in Wallula generally, the application of EPA's Natural Event Policy, including implementation of BACM on agricultural sources to minimize the impacts of windblown dust during natural event exceedances, the attainment determination already made for the area through January 31, 2001, and more recent monitoring data showing continuing attainment, EPA proposes to approve the submitted attainment demonstration for the Wallula serious nonattainment area. 

##                     F. Implementation of Best Available Control Measures on Major Stationary Sources of PM10                     Precursors                 

                    CAA section 189(e) requires BACT to be applied to major stationary sources of PM10                     precursors if these sources contribute significantly to PM10                     exceedances in the area. Analysis of the PM10                     filters on two days with exceedances, two days with elevated concentrations, and two days with low concentrations revealed that dust was the primary material on the PM10                     filters.                           ( print page 5092)                        Based on this information, EPA does not believe major stationary sources of PM10                     precursors contribute significantly to PM10                     levels in excess of the NAAQS in the nonattainment area.                 

## G. Contingency Measures 

Section 172(c)(9) of the Clean Air Act requires that implementation plans provide for the implementation of specific measures to be undertaken if the area fails to make RFP or attain by its attainment deadline. These contingency measures are to take effect without further action by the State or EPA. 67 FR at 64816. 

                    The contingency measures in the serious area plan focus on mitigation of the impacts of windblown dust. The focus is on windblown dust rather than on the circumstances of the July 3, 1997 exceedance because, as discussed above, the circumstances of the July 3, 1997 exceedance were determined to be unusual and unlikely to recur. In contrast, windblown dust events occur regularly in the Columbia Plateau and are the most likely cause of future exceedances. Because of the likelihood of future wind blown exceedances, the plan does not include a PM10                     trigger level for implementing the contingency measures. Rather, the measures are to be implemented on a regular basis regardless of the PM10                     levels measured.                 

                    The plan's contingency measures include improvements to Ecology's process for identifying source contributors when high wind events are occurring, certain PM10                     reduction projects included in Ecology's 2003 NEAP, and Ecology's BACM demonstration and our accompanying review every time a windblown dust exceedance occurs. In light of these measures to mitigate the impacts of high wind events and increase BMP implementation, along with regular evaluation of these measures during review of natural event claims and during attainment determinations, we believe the plan meets the contingency requirements of section 172(c)(9) of the Clean Air Act.                 

## H. Reasonable Further Progress (RFP) and Quantitative Milestones 

                    CAA section 172(c)(2) requires nonattainment plans to provide for reasonable further progress (RFP). Section 171(1) of the CAA defines RFP as “such annual incremental reductions in emissions of the relevant air pollutant as are required by this part (part D of title I) or may reasonably be required by the Administrator for the purpose of ensuring attainment of the applicable national ambient air quality standard by the applicable date.” CAA section 189(c) also requires PM10                     plans demonstrating attainment to contain quantitative milestones which are to be achieved every 3 years until the area is redesignated attainment and which demonstrate RFP. These quantitative milestones should consist of elements that allow progress to be quantified or measured. Addendum at 42016.                 

                    As discussed above, in 2002, EPA determined that Wallula nonattainment area was meeting the 24-hour and annual PM10                     standards as of December 31, 2001. Since then, monitoring data show that Wallula is continuing to meet the standards. Because the area is already in attainment of the standards, the emissions inventory is believed to have changed little since 1997, and control measures are being implemented as a part of the Wallula serious area plan to ensure the Wallula area maintains the standards, EPA believes no further showing of RFP or quantitative milestones are necessary. For these reasons, we propose to find that the plan meets the RFP and milestone requirement in CAA section 189(c)(1).                 

## I. Transportation Conformity 

                    CAA section 176(c) requires that federally-funded or approved transportation plans, programs, and projects in nonattainment areas “conform” to the area's air quality implementation plans. Conformity ensures that federal transportation actions do not worsen an area's air quality or interfere with its meeting the air quality standards. We have issued a conformity rule that establishes the criteria and procedures for determining whether or not transportation plans, programs, and projects conform to a SIP.                     *See*40 CFR part 93, subpart A.                

                    One of the primary tests for conformity is to show transportation plans and improvement programs will not cause motor vehicle emissions higher than the levels needed to make progress toward and meet the air quality standards. The motor vehicle emissions levels needed to make progress toward and meet the air quality standards are set in an area's attainment and/or RFP plans and are known as the “motor vehicle emissions budget.” Emissions budgets are established for specific years and specific pollutants.                     *See*40 CFR 93.118(a).                 

                    Ecology's analysis shows that mobile sources are an insignificant source of PM10                     emissions in the Wallula nonattainment area. As a result, a motor vehicle emissions budget is not required as part of the Wallula serious area plan and transportation conformity does not apply in this area.                     *See*40 CFR 93.109(k).                 

## V. Statutory and Executive Order Reviews 

                    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this proposed action is not a “significant regulatory action” and therefore is not subject to review by the Office of Management and Budget. For this reason, this action is also not subject to Executive Order 13211, “Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use” (66 FR 28355, May 22, 2001). This proposed action merely proposes to approve state law as meeting Federal requirements and imposes no additional requirements beyond those imposed by state law. Accordingly, the Administrator certifies that this proposed rule will not have a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601*et seq.*). Because this rule proposes to approve pre-existing requirements under state law and does not impose any additional enforceable duty beyond that required by state law, it does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4).                 

This proposed rule also does not have tribal implications because it will not have a substantial direct effect on one or more Indian tribes, on the relationship between the Federal Government and Indian tribes, or on the distribution of power and responsibilities between the Federal Government and Indian tribes, as specified by Executive Order 13175 (65 FR 67249, November 9, 2000). This action also does not have Federalism implications because it does not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132 (64 FR 43255, August 10, 1999). This action merely proposes to approve a state rule implementing a Federal standard, and does not alter the relationship or the distribution of power and responsibilities established in the Clean Air Act. This proposed rule also is not subject to Executive Order 13045 “Protection of Children from Environmental Health Risks and Safety Risks” (62 FR 19885, April 23, 1997), because it is not economically significant. 

                    In reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the Clean Air Act. In this context, in the                           ( print page 5093)                        absence of a prior existing requirement for the State to use voluntary consensus standards (VCS), EPA has no authority to disapprove a SIP submission for failure to use VCS. It would thus be inconsistent with applicable law for EPA, when it reviews a SIP submission, to use VCS in place of a SIP submission that otherwise satisfies the provisions of the Clean Air Act. Thus, the requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) do not apply. This proposed rule does not impose an information collection burden under the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501*et seq.*).                 

# List of Subjects in 40 CFR Part 52

      - Environmental protection
      - Air pollution control
      - Intergovernmental relations
      - Particulate matter, and Reporting and recordkeeping requirements

Dated: January 21, 2005. 

Ronald A. Kreizenbeck, 

Acting Regional Administrator, EPA Region 10.

# Footnotes

1.                             The 1990 Amendments to the CAA made significant changes.                         *See*                         Public Law No. 101-549, 104 Stat. 2399. References herein are to the CAA as amended in 1990. The Clean Air Act is codified, as amended, in the United States Code at 42 U.S.C. 7401,                         *et seq.*
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2.                             The moderate area SIP requirements are set forth in section 189(a) of the CAA.                    
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3.                             “State Implementation Plans; General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990,” 57 FR 13498 (April 16, 1992) and 57 FR 18070 (April 28, 1992).                    
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4.                             “State Implementation Plans for Serious PM10                         Nonattanment Areas, and Attainment Date Waivers for PM10                         Nonattainment Areas Generally; Addendum to the General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990,” 59 FR 41998 (August 16, 1994).                    
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5.                             The Wallula serious area plan does not identify significant source contributors to violations of the PM10                         annual standard because, as discussed above, the area has never violated the annual standard.                    
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[FR Doc. 05-1867 Filed 1-31-05; 8:45 am] 

BILLING CODE 6560-50-P