Appendix B – Nonattainment Receptors

1 Technical Support Document for EPA’s Proposed Actio n on the State of Montana’s 2010 Infrastructure State Implem entation Plan (Transport Portion) for the 2006 24-hour Fine Particulate (PM2.5) National Ambi ent Air Quality Standard



### Appendix B – Nonattainment Receptors

1. EPA Region 9 States – Nevada and California

1. Nevada – Washoe County

2. Eastern California – Inyo County

3. Southern California – Los Angeles, Riverside, and S an Bernardino Counties

4. Northern California – Butte, Sacramento, and Sutter Counties
5. Central California – Fresno, Kern, Kings, Merced, S an Joaquin, Stanislaus, and Tulare
Counties
6. California/Mexico Border – San Diego County

2. EPA Region 8 States – Utah

1. Utah – Utah County (Provo-Orem)

2. Utah – Box Elder, Davis, Salt Lake, and Weber Count ies (Greater Salt Lake Area)

3. EPA Region 10 States – Idaho, Oregon, and Washi ngton
1. Idaho/Utah – Franklin County/Cache County

2. Idaho – Shoshone County (Pinehurst)

3. Oregon – Klamath County (Klamath Falls)

4. Oregon – Lake County (Lakeview)
5. Oregon – Lane County (Oakridge)
6. Washington – Pierce County (Tacoma)

7. Washington – Yakima County (Yakima)

Note: See Appendix E for further technical data for Greater S alt Lake Area, Utah.Appendix B – Nonattainment Receptors

2 1.1. Nevada

Nevada – Washoe County

Elevated PM2.5 levels at the Reno receptor generall y occur during wintertime stagnation episodes, with lower levels of PM2.5 during the other times of the year (see Figures 1.6.A thru 1.6.D: PM2.5 24-hour Averages at the Reno PM2.5 Monitoring Site.) Low te mperatures and strong inversions are the dominant contributing factors to the elevated PM2.5 levels:

The year began with several consecutive days of sta ble atmospheric conditions and strong temperature inversions. The lowest temperature of t he month (18 degrees) occurred on January 4. The low temperature and the strong inver sions were contributing factors to a 24-hour PM2.5 concentration and NAAQS exceedance of 38.8 μg /m3 on January 5, 2010. 1

The levels of PM2.5 measured in March through Novem ber in 2008 through 2011 are generally very low. The exception to this is in June and July of 2 008 when wildfires had a large impact on PM2.5 concentrations in this area, and the Washoe County Health District has flagged the affected data as exceptional events. 2 An exceptional events request was submitted to EPA Region IX in October 2009. EPA has not yet taken action on the request.

The wintertime PM2.5 exceedances occur during perio ds of strong inversions and are largely due to local emissions. Therefore, it is reasonable to con clude that emissions from the state of Montana do n ot contribute substantially to exceedances of the PM2. 5 standard at this nonattainment receptor.

1 Washoe County, Nevada Air Quality Trends (2001-201 0), May 2011. http://www.co.washoe.nv.us/repository/files/4/Washo e-County-Air-Quality-Trends-2001-2010.pdf

2 Washoe County, Nevada Air Quality Trends (2002-201 1), May 24, 2012. http://www.co.washoe.nv.us/repository/files/4/Washo e-County-Air-QualityTrends-2002-2011.pdfAppendix B – Nonattainment Receptors

3 Figure 1.1.A: PM2.5 24-hour Averages at the Reno PM 2.5 Monitoring Site for 2008Appendix B – Nonattainment Receptors

4 Figure 1.1.B: PM2.5 24-hour Averages at the Reno PM 2.5 Monitoring Site for 2009Appendix B – Nonattainment Receptors

5 Figure 1.1.C: PM2.5 24-hour Averages at the Reno PM 2.5 Monitoring Site for 2010Appendix B – Nonattainment Receptors

6 Figure 1.1.D: PM2.5 24-hour Averages at the Reno PM 2.5 Monitoring Site for 2011Appendix B – Nonattainment Receptors

7 Figure 1.1.E: Washoe County Ambient Air Monitoring Sites (2002-2011) 3

3 http://www.co.washoe.nv.us/repository/files/4/Washo e-County-Air-QualityTrends-2002-2011.pdfAppendix B – Nonattainment Receptors

8 1.2 Eastern California – Inyo County

Elevated levels of PM2.5 in Inyo County are measure d at a single monitor, the Keeler monitor, which is located adjacent to the Owens Lake Bed. (See Figur es 1.2.A and 1.2.B, below). The Owens Lake Bed is surrounded by steep terrain. (See Figure 1.2.C, bel ow). EPA believes that because of the proximity of the monitor to a large local source of particulate matter, and the steep nearby terrain, it is reasona ble to
conclude that Nevada does not contribute to nonatta inment of the 24-hour PM2.5 standard at this

monitor.

The Owens Valley Planning Area is located in Inyo C ounty in eastern-central California. It is situated at the south end of the deep, long, narrow Owens Valle y with the Sierra Nevada to the west (maximum elevation 14,495 feet), the Inyo Mountains to the e ast (maximum elevation 14,246 feet), and the Coso Range to the south (maximum elevation 8,160 feet) ( Figure 1.2.C). The predominantly dry, alkaline Owens Lake bed is approximately eight miles south o f the community of Lone Pine on U.S. Highway 395, 60 miles north of the city of Ridgecrest, and 35 miles west of Death Valley. The bed of Owens Lake is defined as the area below 3,600 feet above mean sea level (all elevations will be given in fee t above mean sea level). The lake bed extends about s eventeen miles north and south and ten miles east and west and covers an area of approximately 110 sq uare miles (70,000 acres).

Table 1: PM2.5 Levels at the Keeler Monitor

Year Date PM2.5 Level (μg/m3)

2006 December 28 193

2007 March 28

November 11 43
57

2008 March 1

April 15 April 30 May 21 58

48

43

44

2009 March 26

March 29 36
69

2010 June 10 44

Owens Lake is the largest single source of PM-10 in the United States. 4 Water was first diverted from the Owens River to the City of Los Angeles in 1913, and by 1926 Owens Lake was dry. Today, the Owens lakebed produces enormous amounts of windblow n dust in exceedance of federal air pollution standards for particulate matter.

4 http://www.gbuapcd.org/owenslake.htmAppendix B – Nonattainment Receptors

9 Monitoring and research conducted for more than 20 years, as well as three previous State Implementation Plans (SIPs), has determined that wi nd-blown dust from the dry bed of Owens Lake is the dominant cause of NAAQS violations for PM10 in the nonattainment area. 5

Figure 1.2.A: Keeler Dunes 6

5 Final 2008 Owens Valley PM10 Planning Area Demonst ration of Attainment State Implementation Plan, Jan uary 28, 2008. http://www.gbuapcd.org/ovpm10sip.htm

6 http://www.gbuapcd.org/owenslake/dustID/20120516Cur rentSites.Appendix B – Nonattainment Receptors

10 Figure 1.2.B: Owens Lake Dust ID Network MapAppendix B – Nonattainment Receptors

11 Figure 1.2.C: Model domain and one-km mesh size ter rain (m) 7

7 Final 2008 Owens Valley PM10 Planning Area Demonst ration of Attainment State Implementation Plan, Jan uary 28, 2008, Chapter 6, Figure 6.3. http://www.gbuapcd.org/ovpm10sip.htm

.Appendix B – Nonattainment Receptors

12 1.3. Southern California – Los Angeles, Riverside, and San Bernardino Counties

County Site Name Description

Los Angeles Azusa Current monitored values are below 35μg/m 3 . There is a strong
downward trend.

Riverside Mira LomaVan Buren Current monitored values slightly above 35μg/m3. Th ere is a strong

downward trend.

San
Bernardino Fontana Current monitored values slightly above 35μg/m 3 . There is a strong
downward trend.

The high PM2.5 concentrations in the South Coast Ai r Basin are mainly due to the secondary formation of smaller particulates resulting from mobile, stat ionary and area source emissions of precursor gases (i.e., NOx, SOx, NH4, and VOC) that are converted t o PM in the atmosphere.

Speciated PM2.5 data at the Central Los Angeles Sit e (CELA) and the Rubidoux site (RIVR) indicate that organic carbon, ammonium nitrate, and ammonium sulfate constitute the major components at each site (shown in Figures 1.3.A and 1.3.B, below). 24 -hour PM2.5 design value trends show strong

downward trend at all sites in the South Coast Basi n (shown in Figure 1.3.C, below). 8

PM2.5 is essentially a combustion generated polluta nt due to the volume of traffic flow and numbers of sources (both point and area) located in the region . It is important to note that the areas with the h ighest concentrations are directly downwind of an area wit h major ammonia sources associated with dairies and poultry farming. 9

The South Coast Air Quality DRAFT 2012 Air Quality Management Plan 10 air quality projections show that the emission control strategy outlined in the plan will result in air quality improvement at each of the nonattainment receptors, and that each of these sites will attain the standard in 2014 or sooner ( see Figure 1.3.D: Maximum 24-Hour Average PM2.5 Design Concentrations: 2008 Baseline, 2014 and 2014 Controlled).

The spatial distribution of PM2.5 in the South Coas t Basin supports the fact that it is largely of loc al origin. The air quality trends and projections ind icate that the emission strategy is effective in re ducing PM2.5. Additionally, Montana is quite distant from these receptors. Therefore, it is reasonable to conclude that transport from Montana does not contr ibute substantially to violations of the 2006 PM2.5 standard at these receptors.

8 Joe Cassmassi, Scientific, Technical & Modeling Pe er Review (STMPR) Advisory Group Meeting, September 22, 2011.

9 Final 2007 Air Quality Management Plan (AQMP), App endix V – Modeling and Attainment Demonstrations Ju ne, V-2-10.

10 http://www.aqmd.gov/aqmp/2012aqmp/draft/Chapters/Ch 5.pdfAppendix B – Nonattainment Receptors

13 Figure 1.3.A: Speciated data for Central Los Angele s 11

11 STMPR Item # 5 - 2008 PM2.5 Air Quality Characteri zation, January 19, 2012. Bong-Mann Kim.Appendix B – Nonattainment Receptors

14 Figure 1.3.B: Speciated PM2.5 data for the Rubidoux site in Riverside County 12

12 STMPR Item # 5 - 2008 PM2.5 Air Quality Characteri zation, January 19, 2012. Bong-Mann Kim.Appendix

Figure 1.3 .C B – Nonattainment Receptors

15 .C: 24-hour PM2.5 Design Value TrendsAppendix B – Nonattainment Receptors

16 Figure 1.3.D: Maximum 24-Hour Average PM2.5 Design Concentrations:

2008 Baseline, 2014 and 2014 Controlled 13

13 http://www.aqmd.gov/aqmp/2012aqmp/draft/Chapters/Ch 5.pdfAppendix B – Nonattainment Receptors

17 1.4. Northern California – Butte, Sacramento, and S utter Counties

County Site Name Description

Butte Chico This receptor is in the Chico nonattainment area.

The monitored exceedances likely reflect localized sources occurring during wintertime temperature inversions with low w inds that persist for several days in an area that trap emissions tog ether with complex topography. The speciation data from high concentr ation days
indicates that as much as 75% of the concentrations are due to organic carbon, which also indicates that residential wood burning emissions are the dominant source. Also, about 70% of the emi ssions are estimated to be from area sources, of which residen tial wood burning is the dominant source, contributing 2.65 of the 6.4 t ons per day (ARB Almanac website (2006) http://www.arb.ca.gov/ei/maps/statemap/cntymap.htm )

Sacramento SacramentoDel Paso

Manor This receptor is in the Sacramento Metro nonattainm ent area.

The monitored exceedances likely reflect localized sources occurring during wintertime temperature inversions with low w inds that persist for several days. The speciation data on days durin g cold seasons in 2004-2006 with the highest 5 percentile of PM2.5 co ncentrations show that the mass is 47-60% total carbon mass (TCM), wh ich indicates residential wood burning as a significantly contrib uting source ( http://www.epa.gov/pmdesignations/2006standards/fin al/TSD/tsd_F_li mited_2004-06_speciation_data_report.pdf ).

The largest single source of Sacramento's wintertim e PM2.5 emissions is wood and other solid fuel burning in fireplaces, wood inserts, wood stoves and pellet stoves.

There is a strong downward trend in this area in re cent years (http://www.epa.gov/region9/air/trends/pm25.html).

Sutter Yuba City Yuba City-Marysville

The monitored exceedances likely reflect localized sources occurring during wintertime temperature inversions with low w inds that persist for several days.

There is a strong downward trend and preliminary 20 09-2011 data indicates the area may be attaining the standard. (http://www.epa.gov/region9/air/trends/pm25.html).Appendix B – Nonattainment Receptors

18 The Northern Sacramento Valley Air Basin is bounded on north and west by the Coastal Mountain Range and on the east by the southern portion of th e Cascade Mountain Range and the northern portion of the Sierra Nevada Mountains. These mountain rang es reach heights in excess of 6,000 feet with peaks rising much higher. This provides a substantial ph ysical barrier to locally created pollution.

For the areas under consideration, high PM2.5 conce ntrations mostly occur during stagnant conditions during winter, with radiation inversions. The cooli ng of the ground, as heat is radiated away, creates an inversion, since air near the ground is cooler than that above. This inhibits mixing and confines pollutants to a relatively shallow layer near the g round. A typical value for maximum mixing height during high PM2.5 conditions is 300 meters (984 fee t) AGL (above ground level). EPA recognizes that an inversion height is not a rigid boundary extendi ng through a fixed elevation. In reality the invers ion would be partly terrain-following, and the degree o f stagnation would be subject to additional influen ces at the foothill edges, such as strong diurnal slope flows. In any case, mixing heights vary by site a nd date, so any single height can provide only a scale for comparison, not a definitive value. Neverthele ss, the inversion height provides an indicator of the a rea over which inversions may be enhancing pollutio n concentrations, and of the extent of the area that may be contributing to NAAQS violations.

Because these areas in Northern California have top ographical features higher than the typical daytime height of the inversion layer, EPA considered the i nversion height to estimate the size of the area li kely to have similar pollution conditions and to contrib ute to NAAQS violations. For example, the eastern portion of Butte County extends into the foothills of the Sierra Nevada Mountains. For Chico, the 300 meters AGL (984 feet) inversion layer thickness tra nslates to an elevation contour of 375 m (1221 feet ) MSL (above Mean Sea Level). Much of eastern portio n Butte County is above this elevation, as shown in Figure 1.4.B below.

In summary, topography is an important factor in th ese areas, given that the inversion layer, which ca n lead to winter PM2.5 exceedances in the Sacramento Valley, is blocked by the Sierra foothills.

The steep terrain and speciated PM2.5 data at these Northern California receptors supports the fact th at the PM2.5 is largely of local origin. This, combine d with the distance between these receptors and Montana, make it reasonable to conclude that transp ort from Montana does not contribute substantially
to violations of the 2006 PM2.5 standard at these r eceptors.Appendix B – Nonattainment Receptors

19 Figure 1.4.A: Average Composition on 14 Exceedance Days - Chico Average Composition on 14 Exceedance Days- Chico

AmmNitrate

16%

AmmSulfate

2%

OC

75% Other

2% Geological

1% Elements

2%

EC

2%

PM2.5 Mass= 52.2 ug/ m3

Sum of Species=51.4 ug/ m3Appendix B – Nonattainment Receptors

20 Figure 1.4.B: Map of Butte County PM2.5 Nonattainme nt AreaAppendix B – Nonattainment Receptors

21 1.5. Central California – Fresno, Kern, Kings, Merc ed, San Joaquin, Stanislaus, and Tulare
Counties

County Site Name

Fresno Fresno-1st Street

Kern Bakersfield-Planz Road Kings Corcoran

Merced Merced-M Street San Joaquin Stockton-Hazelton

Stanislaus Turlock

Tulare Visalia

PM2.5 levels in the San Joaquin Valley are generall y highest in the months of January, February, November and December (see Figure 1.5.A, below). P M2.5 builds up in episodes of several days or weeks. These episodes generally occur during perio ds with stagnation, cool temperatures, high humidity, and low mixing depths. 14 The peak day composition of PM2.5 at Bakersfield is primarily ammonia nitrate (67%) and organic carbon (16%).

The primary sources of PM2.5 in the region are dies el engines (nitrate), gasoline engines (nitrate), a nd agricultural activities (ammonium) which contribute regionally. Wood smoke (organic carbon) and diesel engines (elemental carbon) contribute to the elevated levels of PM2.5 in urban areas.

Because PM2.5 builds up in episodes of several days or weeks, during periods with stagnation, and low mixing depths, it is reasonable to conclude that lo ng range transport does not contribute to elevated levels PM2.5 in the San Joaquin Valley. Therefore, EPA believes it is reasonable to conclude that

Montana does not contribute to nonattainment of the 24-hour PM2.5 standard at these receptors.

14 Nature of PM2.5 in the San Joaquin Valley, Karen Magliano, California Air Resources Board, Technical Symposium April 27, 2012.Appendix B – Nonattainment Receptors

22 Figure 1.5.A: Monthly Average PM2.5 Concentration i n Bakersfield CaliforniaAppendix B – Nonattainment Receptors

23 Figure 1.5.B: 2008-2010 Peak Day Composition in Bak ersfieldAppendix B – Nonattainment Receptors

24 1.6. California/Mexico Border – San Diego County

This receptor’s status is based on a single high va lue of 114 μg/m 3 , measured on June 1, 2010. Measured values of PM2.5 at the La Posta site are very low f or other days. On June 1, 2010, the La Posta monit or recorded the highest measured 24-hour PM2.5 value i n all of California (99% of values for the rest of the State were below 20 μg/m3). Given the very low levels of PM2.5 measured at all other sites on the only day above 35μg/m 3 , and the large distance between this receptor and Montana sources, it is reasonable to conclude that there is not a signific ant contribution to the elevated PM2.5 levels from emissions of PM2.5 or PM2.5 precursors from the sta te of Montana to this receptor.

2. EPA Region 8 States – Utah 15

2.1. Utah – Utah County (Provo-Orem)

A large portion of Utah County is designated as the Provo 2006 PM2.5 nonattainment area (NAA).

The Provo NAA is situated in the Utah Valley. Like the other low-lying valleys just west of the Wasatc h Front, the topography of the Utah Valley makes it p rone to temperature inversions. During inversions, the Provo NAA features stagnant air masses and calm to light winds. As the airshed is essentially capped, PM2.5 is formed in-situ (and trapped) via f resh locally derived emission sources and secondary chemistry. Transport of air masses between the Salt Lake City and Provo NAAs can occur during inversions, as there is a 4.75-mile gap in the moun tains separating these airsheds which is below the approximate average inversion height for these area s.

Speciation data from exceedance days from 2004-2006 showed the average composition of PM2.5 in Provo is 71% ammonium nitrate, with 21% carbon and organic compounds, 8% ammonium sulfate, and
2% crustal.

Several factors, including significant mobile, poin t and area sources contribute to primary and secondarily formed PM2.5 that violate the standard during stable weather events associated with strong
inversions. Because of the local nature of these ev ents, it is reasonable to conclude that emissions f rom Montana do not interfere with the maintenance of th e 24-hour PM2.5 standard at nonattainment receptors in the Provo-Orem NAA.

2.2. Utah – Box Elder, Davis, Salt Lake, and Weber Counties (Greater Salt Lake Area)

(Site names: Brigham City, Ogden-Clearfield, and Sa lt Lake City)

All of Davis and Salt Lake counties and portions of Box Elder, Tooele and Weber counties are designated as part of the Salt Lake City 2006 PM2.5 nonattainment area.

The SLC NAA is situated in a valley bordered on the west by the Stansbury Mountains, Promontory Mountains and Great Salt Lake, and on the east by t he Wasatch Front. During inversions, the NAA becomes a closed airshed (save for potential transp ort between the Salt Lake City and Provo NAAs) featuring stagnant air masses and light winds which typically oscillate back and forth within the airs hed.

15 For discussion of the Idaho/Utah – Franklin County /Cache County area, see section 3.1 of this Appendix.Appendix B – Nonattainment Receptors

25 As the airshed is essentially capped during inversi ons, PM2.5 is formed in-situ (and trapped) via fres h locally derived emission sources and secondary chem istry.

Speciation data from exceedance days from 2004-2006 showed the average composition of PM2.5 in Salt Lake City is 58% ammonium nitrate, 31% carbon and organic compounds, 8% ammonium sulfate,
and 2% crustal.

Several factors, including significant mobile, poin t and area sources contribute to primary and secondarily formed PM2.5 that violate the standard during stable weather events associated with strong
inversions. Because of the local nature of these ev ents, it is reasonable to conclude that emissions f rom Montana do not interfere with the maintenance of th e 24-hour PM2.5 standard at nonattainment receptors in the SLC NAA.

3. EPA Region 10 States – Idaho, Oregon, and Washin gton

3.1. Idaho/Utah – Franklin County/Cache County

Portions of Franklin County, Idaho and Cache County , Utah are designated as part of the Cache Valley 2006 PM2.5, two-state, nonattainment area.

Limited chemical speciation data in the Cache Valle y indicates the PM2.5 problem is dominated by

ammonium nitrate aerosol similar to nonattainment a reas along the Wasatch front in and near Salt Lake City. The chemical speciation monitor in Bountiful is closest to the Cache Valley and is considered broadly representative of conditions in the Cache V alley.

The ridge dominated synoptic meteorology during PM2 .5 cold pool episodes features weak transport winds and near calm surface winds. As a result, tra nsport of PM2.5 and precursors from the rural regio ns at the domain periphery is very small. In addition, most of the observed Wasatch Front and Cache Valley PM2.5 is formed in-situ (and trapped) via fr esh locally derived emission sources and secondary chemistry.

Local heating emissions from woodstoves, emissions from agricultural activities, and mobile emissions contribute to primary and secondarily formed PM2.5 that violate the standard during stable weather events associated with extremely strong inversions.

These emissions and the related effects are limited to the Cache Valley, as they are trapped there due to temperature inversions, low wind, and local topogra phy. The rest of the county is very sparsely populated with no significant sources that can cont ribute to a violation of the PM2.5 standard at the

Franklin monitor.

EPA Region 10 Positive Matrix Factor (PMF) receptor modeling identified 11 factors contributing to
elevated wintertime PM2.5 at the Bountiful monitori ng site including nitrate rich (56%), ammonium chloride (15%), wood smoke (10%), organic pyrolysis rich (6%), sulfate rich (5%) and smaller contributions by other identified factors (gasoline vehicles, 2 soil factors, fireworks, iron rich, an d urban unidentified).

3.2. Idaho – Shoshone County (Pinehurst)Appendix B – Nonattainment Receptors

26 State information indicates that emissions from woo dstoves contribute to primary PM2.5 that violates the standard during stable weather events associate d with strong inversions. These emissions and the related effects are limited to the city of Pinehurs t airshed, as they are trapped there due to tempera ture inversions, low wind and local topography. Due to the highly localized nature of the PM2.5 pro blem in Pinehurst, it is reasonable to conclude that emissi ons from the state of Montana do not significantly
contribute to exceedances of the PM2.5 standard at this receptor.

The rest of the county is very sparsely populated w ith no significant sources that can contribute to a
violation of the PM2.5 standard at the Pinehurst mo nitor.

3.3. Oregon – Klamath County (Klamath Falls)

A portion of Klamath County is designated nonattain ment for the 2006 PM2.5 NAAQS. Klamath Falls is a relatively small urban community located in an d supporting a vast rural area in south-central Oregon.

State analysis includes a 2005 emission inventory t hat shows that wood stove emissions are the most significant source of emissions. Additional air qua lity monitoring data provide supporting evidence th at residential wood combustion emissions are the prima ry cause of exceedance days.

Data shows exceedances occur during winter months, at a time when woodstoves are contributing to
smoke in the area. Exceedances occurred from Decem ber through January, corresponding directly with the winter wood heating season and indicate the exc eedances are a seasonal occurrence except flagged

wildfire events.

Speciation data analysis indicates most of the PM2. 5 comes from elemental and organic carbon, typical

indicators of combustion activities such as wood bu rning.

Meteorological data from Klamath Falls show that lo w wind speeds dominate during violating days, and the Klamath Falls area experiences frequent winter- time nocturnal inversions, when PM pollution can build up over time.

Diurnal concentrations of PM2.5 are observed by hou rly light scatter data that correspond closely with night-time use of woodstoves.

Night-time inversions coupled with low wind speeds strongly suggest that pollution in the Klamath Fall s area is a localized effect heavily influenced by th e use of woodstoves. Due to the highly localized na ture of the PM2.5 problem in Klamath Falls, it is reason able to conclude that emissions from the state of Montana do not contribute substantially to exceedan ces of the PM2.5 standard at this receptor.

EPA Region 10 PMF receptor modeling identified the 6 factors contributing to elevated wintertime PM2.5 including wood smoke (65%), organic pyrolysis rich (23%) and smaller contributions by other identified factors (nitrate rich, soil, sulfate ric h, and urban unidentified).

3.3. Oregon – Lake County (Lakeview)

EPA Region 10 PMF receptor modeling identified 7 fa ctors contributing to PM2.5 including wood smoke (67%), organic pyrolysis rich (13%), nitrate rich (7%), soil (5%) and smaller contributions by other identified factors (sulfate rich and urban un identified).Appendix B – Nonattainment Receptors

27 3.4. Oregon – Lane County (Oakridge)

A portion of Lane County is designated nonattainmen t for the 2006 PM2.5 NAAQS.

EPA’s technical analysis points to residential home heating using wood burning appliances as being the main contributors to fine particle pollution in thi s area.

EPA Region 10 PMF receptor modeling identified 7 fa ctors contributing to elevated wintertime PM2.5 including wood smoke (76%), organic pyrolysis rich (15%) and smaller contributions by other identified factors (gasoline vehicles, iron rich, sulfate rich , sea salt, and soil).

3.5. Washington – Pierce County (Tacoma)

(Site name: Tacoma-South L Street)

A portion of Pierce County (Tacoma) is designated n onattainment for the 2006 PM2.5 NAAQS.

The state analysis indicates that wood smoke associ ated with home heating is the largest source of PM2.5 in the Tacoma-Pierce County nonattainment are a.

The state data asserts that the PM2.5 problem is hi ghly localized. Surface measurements at multiple sites suggest that the only design values which vio late the 2006 PM2.5 NAAQS are in the core of the nonattainment area, within about 3 km of the South L Street monitor. Beyond about 3-5km, the design values drop and are well below the NAAQS.

On-site sonic anemometer and vertical temperature p rofile measurements revealed that exceedances only occurred: in winter; at night; when there was a surface inversion; below an ambient temperature o f about 50F; when wind speeds were less than 1.5 mph.

Within 3km of the South L Street monitor, during th e season in which the violations occur, wood smoke is the largest source, on-road mobile is second but appears to be significantly smaller, industrial an d other sources make up the remainder and are minor.

EPA Region 10 PMF receptor modeling identified 10 f actors contributing to elevated wintertime PM2.5 including wood smoke (60%), organic pyrolysis rich (10%), nitrate rich (7%), iron rich (7%), sulfate rich (5%) and smaller contributions from other iden tified factors (gasoline vehicles, sea salt, soil, aged sea salt, and a 2 nd sulfate rich factor).

Due to the highly localized nature of the PM2.5 pro blem in Tacoma, it is reasonable to conclude that
emissions from the state of Montana do not contribu te substantially to exceedances of the PM2.5 standard at this receptor.

3.6. Washington – Yakima County (Yakima)

EPA Region 10 PMF receptor modeling identified 10 f actors contributing to elevated wintertime PM2.5 including wood smoke (24%), nitrate rich (24%), gas oline vehicles (16%), organic pyrolysis rich (9%), sulfate rich (7%) and smaller contributions from ot her identified factors (iron rich, sea salt, soil, zinc rich, and urban unidentified).