### - 1

- 

## Review of Evidence Regarding Claimed Exceptional Events Leading to 24

- hour PM 2.5 

## Exceedances

Shasta County, CA

June 23, 2008 July 23 , 2008



## Plumas County, CA

June 23 , 2008

June 26 , 2008 July 11 , 2008 July 19, 2008 July 23, 2008



### US Environmental Protect ion Agency Region 9

March 11, 2010

### - 2

-

Contents

1.0 Introduction

................................ ................................ ................................ ........................... 3

2.0 Summary of the Events

................................ ................................ ................................ ......... 3

3.0 Requirements of the Exceptional Events Rule

................................ ................................ ...... 5

4.0 Criteria Set Forth in 40 CFR § 50.1(j)

................................ ................................ .................. 6

4.1 Affects Air Quali ty

................................ ................................ ................................ ............ 6

4.2 Not Reasonably Controllable or Preventable

................................ ................................ .. 10

4.3 Natural Event

................................ ................................ ................................ ................... 10

5.0 Clear Causal Relationship

................................ ................................ ................................ ... 11

6.0 Concentrations in Excess of Normal Historical Fluctuations

................................ ............. 15

7.0 No Exceedan ce But For the Event

................................ ................................ ...................... 18

8.0 Procedural Requirements

................................ ................................ ................................ .... 20

9.0 Conclusion

................................ ................................ ................................ .......................... 21

10.0 Citation of Exceptional Event Request Documentation

................................ .................. 21

Tables

Table 1: Summer 2008 PM 2.5 Flagged Events Under Review......................................................5

Table 2: Federal Wildland Fire Incidents in Northern California

– June 20 to September 7,

2008.........................................................................................................................8 Table 3. Levoglucosan Levels, Portola

- Summer 2007 and 2008..............................................14 Table 4. Portola Monitor: Highest PM 2.5 concentrations, Summers (Jun

- Aug) 2000

- 2008................15

Table 5. Quincy Monitor: Highest PM 2.5 concentrations, Summers (Jun

- Aug) 2000

- 2008................16 Table 6. Redding Monitor: Highest PM 2.5 concentrations, Summers (Jun

- Aug) 2000

- 2008...............17

Figures

Figure 1: Summer 2008 California Wildfires and Presidentially D eclared Emergency Areas................4 Figure 2: Major Federal Wildfires Burning in California June 20

– September 7, 2008, and PM 2.5 (FRM, FEM, and BAM) Monitoring Sites in California... ..................................................................7 Figure 3 : Wildfires Ignited June 20

– July 23, 2008 near the Redding, Portola, and Quincy PM 2.5 monitors.............................. ....................................................................................11 Figure 4 : PM 2.5 concentrations recorded at Redding, Portola, and Quincy

, June

– August 2008

...... ......1 2 Figure 5 . NOAA Satellite Image, June 23, 2008........................................... ........................1 3 Figure 6. Wood Burning Markers (Levoglucosan, Galactosan, Mannosan) at Portola during the Summer 2008 Wildfires, compared to Summer Average. ..................................................................14 Figure 7. Distribution of Summer (June

– August) PM 2.5 FRM Concentrations a t Portola, 2000

- 2008.......................................................................................................................16 Figure 8. Distribution of Summer (June

– August) PM 2.5 FRM Concentrations at Quincy, 2000

- 2008.......................................................................................................................17 Figure 9. Distribution of Summer (June

– August) PM 2. 5 FRM Concentrations at Redding, 2000

- 2008.......................................................................................................................18 Figure 10. Quincy PM 2.5 Concentrations: June

– August, 2000

- 2008..........................................19 Figure 11. Redding PM 2.5 Concentrations: June

– August, 2000

- 2008.........................................19 Figure 12. Portola PM 2.5 Concentrations: June

– August, 2000

- 2008........................................20

### - 3

-



## 1.0 Introduction

On March 22, 2007, EPA adopted a final rule, Treatment of Data Influenced by Exceptional Events 1


### (EER) to govern the review and handling of certain air qualit y monitoring data for which the normal planning and regulatory processes are not appropriate. Under the rule, EPA may exclude data from use

in determinations of National Ambient Air Quality Standard ( NAAQS ) exceedances and violations if a

state demonstrat es that an “exceptional event” caused the exceedances. Before EPA can exclude data from these regulatory determinations, the state must flag the data in EPA‟s Air Quality System (AQS) database and, after notice and opportunity for public comment, submit a demonstration to justify the exclusion. After considering the weight of evidence provided in the demonstration, EPA decides whether or not to concur with each flag.

On August 28, 2009, California‟s Air Resources Board (CARB) submitted a preliminary

demo nstration for high

- PM 10 

### and PM 2.5 

### events that occurred at various monitoring locations throughout California on twenty

- seven separate days in the summer of 2008. Additional clarification was submitted to EPA via email on January 19, 2010 and January 26, 2 010.

This document sets forth the legal and factual basis for EPA‟s decision regarding specific wildfire

related events that allegedly caused exceedances of the 24

- hour PM 2.5 

### standard in the summer of 2008 at: the Redding, Shasta County monitor on June 23 and July 23, 2008; the Portola, Plumas County monitor on June 23, June 26, July 11, and July 23, 2008; and the Quincy, Plumas County monitor on June 23 and July 19, 2008.



## 2.0 Summary of the Events

In the summer of 2008, California experienced a confluen ce of events resulting in one of California‟s worst summer fire seasons in history. In June 2008, California‟s governor declared a statewide drought, the first time a California statewide drought declaration had ever been made. 2 

### Then, starting

on June 20 , 2008, a series of thunderstorms hit California. Lightning strikes ignited hundreds of fires throughout Northern and Central California. On June 28, 2008, the President of the United States declared a state of emergency for seven counties due to emergen cy conditions resulting from

wildfires. 3 

### On July 4, four more counties were added to the list. 4 

### All told, the fires burned over one

million acres. 5



### Figure 1 is a map noting size, start date, and location of Summer 2008 California fires. It also shows the eleven counties declared emergency areas due to wildfires.

1 135 60 Federal Register / Vol. 72, No. 55 / Thursday, March 22, 2007 / Rules and Regulations.

2 http://www.water.ca.gov/drought/docs/CalDrought.pdf . “Recent California Drought,” California D epartment of Water Resources. Retrieved February 5, 2010.

3 http://www.fema.gov/news/newsrelease.fema?id=44432 “President Declares Emergency Disaster for California,” Federal Emergency Management Agency. Retrieved February 5, 2010.

4 http://www.fema.gov/news/dfrn.fema?id=10853 . “Federal Register Notice for California; Amendment No. 1 to Notice of an Emergency Declaration,” Fe deral Emergency Management Agency. Retrieved February 5, 2010.

5 http://www.bloomberg.com/apps/news?pid=newsarchive&sid=aNDa4mhKUxCU . “California Fires Ravage

Record Ac reage, Spare Economy (Update 1),” Bloomberg.com. Retrieved February 5, 2010.

### - 4

-

Figure 1: Summer 2008 California Wildfires and Presidentially Declared Emergency Areas.

### - 5

-

Smoke contains significant amounts of particulate matter and can adversely impact air quality. CARB operates air monitors throughout California, including Federal Reference Method (FRM) monitors at Portola and Quincy in Plumas County, and Redding in Shasta County. In the summer of 2008, monitors throughout Northern and Central California recorded e xceedances of the 24

- hour PM 2.5 

### standard. This document addresses the exceedances listed in Table 1 that occurred at the Portola, Quincy, and Redding monitors. CARB flagged the events listed in Table 1 and requested the data be excluded as exceptional ev ents due to effects of the Summer 2008 wildfires. This document addresses these specific days and monitor s, and does not discuss the remaining PM 2.5 

### or PM 10 

### Summer 2008 flags . This does not imply that EPA will either concur or not concur on the remaining events.

Table 1 : Summer 2008 PM 2.5 

### Flagged Events Under Review

Date Monitor PM 2.5 

### ( μg /m 3 

### )
June 23, 2008 Redding Monitor (06

- 089

- 0004

- 01), Shasta County 97.1

“ “ Portola Monitor (06

- 063

- 1009

- 01), Plumas County 41.2

“ “ Quincy Monitor (06

- 063

- 1006

- 01 ), Plumas County 142.2
June 26, 2008 Portola Monitor (06

- 063

- 1009

- 01), Plumas County 113.5 July 11, 2008 Portola Monitor (06

- 063

- 1009

- 01), Plumas County 56.0 July 19, 2008 Quincy Monitor (06

- 063

- 1006

- 01), Plumas County 133.0 July 23, 2008 Redding Monit or (06

- 089

- 0004

- 01), Shasta County 200.2

“ “ Portola Monitor (06

- 063

- 1009

- 01), Plumas County 68.6



## 3. 0 Requirements of the Exceptional Events Rule

Pursuant to 40 CFR §50.14(c)(3)(iii) a request for EPA‟s concurrence on an exceptional event flag

must be accompanied by a demonstration that:

(A) The event satisfies all of the criteria set forth in 40 CFR §50.1(j). It :

affects air quality ; is not reasonably controllable or preventable ; and

is caused by human activity that is unlikely to recur at a part icular location, or is a natural

event ;

(B) There is a clear causal relationship between the measurement under consideration and the event that is claimed to have affected the air quality in the area;

(C) The event is associated with a measured concent ration in excess of normal historical fluctuations

, including background; and

(D) There would have been no exceedance or violation but for the event

.

The EER also has p ro cedural requirements. 40 CFR §50.14(c)(2)(iii) requires that data claimed to be

du e to an ex ceptional event be flagged in the AQS database, and that an initial description of the event

### - 6

-

be provided to EPA; both must occur by July 1 of the year following the event. In addition, 40 CFR §50.14(c)(3)(i) requires that the State:

submit a dem onstration to EPA within three years of the calendar quarter of the event or 12 months prior to an EPA regulatory decision ; provide notice and opportunity for public comment ; and submit any public comments along with the demonstration.

The following secti ons evaluate CARB‟s demonstration for the days and events in question with respect to these requirements.



## 4. 0 Criteria Set Forth in 40 CFR § 50.1(j)

4.1 Affects Air Quality

As stated in the preamble to the EER

, the event in question is considered to ha ve affected air quality if it can be shown that there is a clear causal relationship between the monitored exceedance and the event, and that the event is associated with a measured concentration in excess of normal historical

fluctuations. 6 

### These criteri a are discussed in detail in sections five and six below.

Smoke is made up of gas and particulate matter, and can adversely affect air quality. In the summer of 2008, Northern California experienced an extreme fire season. From June 20

– July 22, 2008, a series of thunderstorms produced over 6,000 lightning strikes throughout Northern and Central California. These ignited numerous wildfires in over 26 counties that consumed over one million acres before containment on July 29. 7 

### On June 28, seven counti es were declared disaster areas, including Butte, Shasta, and Trinity Counties

. 8 

### By July 4, four more counties were declared disaster areas, including Plumas County. 9



### Figure 2 shows the fires that started between June 20, 2008 and September 7, 2008 as well as CARB‟s

Federal Reference Method ( FRM ), Federal Equivalent Method (FEM), and Beta Attenuation Method (BAM) PM 2.5 

### air monitors. The specific fires are listed in Table 2.

6 See 72 FR 13569, 72 FR 49051, and 73 FR 14702.

7 August Natural Events Documentation (NED), p. 5

. 8 http://w ww.fema.gov/news/newsrelease.fema?id=44432 “President Declares Emergency Disaster for California,” Federal Emergency Management Agency. Retrieved February 5, 2010.

9 http://www.fema.gov/news/d frn.fema?id=10853 . “Federal Register Notice for California; Amendment No. 1 to Notice of an Emergency Declaration, ” Federal Emergency Management Agency. Retrieved February 5, 2010.

### - 7

-

Figure 2: Major Federal Wildfires Burning in California June 20

– Septemb er 7, 2008, and

PM 2.5 

### (FRM, FEM, and BAM) Monitoring Sites in California.

### - 8

-

Table 2: Federal Wildland Fire Incidents in Northern California

– June 20 to September 7, 2008.

Map

Number Incident

Number Incident Name Latitude Longitude Size (acres) Star t Date Controlled

Date

1 CA

- SRF

1057 Blue 41.5664

- 123.8217 225 6/20/2008

2 CA

- SRF

1224 Blue 2 41.5664

- 123.8217 9,728 6/20/2008

3 CA

- SRF

1123 Hell's Half 40.7511

- 123.5956 15,146 6/20/2008

4 CA

- HUU

003384 Humboldt Complex 40.3994

- 123.9494 1,3 25 6/20/2008

5 CA

- SHF

1041 LIME COMPLEX 40.5342

- 123.4508 99,585 6/20/2008

6 CA

- SRF

1120 Mad Complex 40.3047

- 123.5364 3,705 6/20/2008

7 CA

- MEU

004608 MEU Lightning

Complex 39.5139

- 123.2083 54,819 6/20/2008 11/4/2008

8 CA

- CZU

005581 TRABING 36.9319

- 121.8089 630 6/20/2008 6/24/2008

9 CA

- SRF

1126 Ukonom

- South

Complex 41.3547

- 123.5364 58,871 6/20/2008

10 CA

- SHF

001079 ALPS COMPLEX 40.9194

- 123.2381 1,218 6/21/2008

11 CA

- TNF

1011 American River

Complex 39.1439

- 120.6725 20,541 6/21/2008

12 CA

- LPF

1649 Basin Complex 36.2103

- 121.7394 162,818 6/21/2008

13 CA

- BEU

002390 BROWN 36.7622

- 121.1750 3,870 6/21/2 008 6/24/2008

14 CA

- BTU

007660 BTU Lightning

Complex 39.8797

- 121.4000 64,995 6/21/2008 10/3/2008

15 CA

- PNF

000539 Canyon Complex 39.7039

- 121.2483 47,680 6/21/2008 10/1/2008

16 CA

- LNF

2713 CUB Complex 40.1808

- 121.5622 19,718 6/21/2008

17 CA

- KN F

002970 Gould 41.2003

- 123.0464 229 6/21/2008 7/2/2008

18 CA

- SHF

1057 Iron & Alps

Complexes 40.7325

- 123.0539 105,805 6/21/20 08

19 CA

- MNF

000579 June ABCD

Complex 39.5025

- 122.2025 3,000 6/21/2008

20 CA

- KNF

3393 Klamath Theater 41.6600

- 123.1850 192,038 6/21/2008

21 CA

- LNF

002729 LNF June Lightning

Complex 40.3750

- 120.6250 200 6/21/2008 7/3/2008

22 CA

- MMU

0080 48 Mariposa Complex 37.3450

- 120.2142 2,500 6/21/2008 6/24/2008

23 CA

- STF

1063 North Mountain 37.8833

- 119.8792 2,889 6/21/200 8

24 CA

- MMU

008107 OLIVER 37.4511

- 119.7533 2,789 6/21/2008

25 CA

- SNF

0715 OLIVER COMPLEX 37.4511

- 119.7533 1,000 6/21/2008

26 CA

- LNF

002745 Peterson 40.9114

- 121.3789 1,200 6/21/2008

27 CA

- LNF

002782 Peterson Complex 40.9000

- 121.3333 7, 842 6/21/2008

28 CA

- LMU

2725 Popcorn 40.9347

- 121.3342 3,000 6/21/2008

29 CA

- SHU

004727 SHU LIGHTNING

COMPLEX 40.5708

- 122.3558 86,500 6/21/2008

### - 9

-

Map

Number Incident

Number Incident Name Latitude Longitude Size (acres) Star t Date Controlled

Date

30 CA

- SNF

- 718 SILVER COMPLEX 36.4392

- 119.6772 1,161 6/21/2008

31 CA

- KNF

002975 Siskiyou / Blue 2

Complex 41.5894

- 123.5800 82,186 6/21/2008

32 CA

- MNF

- 645 SODA COMPLEX 39.3750

- 122.9756 8,632 6/21/2008

33 CA

- TGU

4245 TGU LIGHTNING

COMPLEX 40.1872

- 122.2069 22,907 6/21/2008 7/6/2008

34 CA

- WNP

1095 Whiskeytown

Complex 40.6000

- 122.6333 6,420 6/21/2008

35 CA

- LNU

004790 WILD 38.3000

- 122.2044 NR 6/21/2008 6/26/2008

36 CA

- MNF

000663 Yolla Bolly Complex 40.0703

- 122.9 653 NR 6/21/2008 9/15/2008

37 CA

- TNF

1015 Yuba River

Complex 39.3664

- 120.8206 4,254 6/21/2008

38 CA

- LNF

002776 Antelope 40.2519

- 121.8664 600 6/22/2008

39 CA

- SCU

3094 HUMMINGBIRD 37.0353

- 121.6553 794 6/22/2008

40 CA

- LNF

002777 Mill 40.1503

- 121.8475 1,500 6/22/2008

41 CA

- LNF

002781 Mill Complex 40.1503

- 121.8475 2,100 6/22/2008

42 CA

- CZU

005708 Quarry 37.6847

- 122.4033 300 6/22/2008 6/29/2008

43 CA

- LNU

004843 WALKER 39.0714

- 122.4947 NR 6/22/2008 7/3/2008

44 CA

- SCU

003091 WHI TEHURST 37.0100

- 121.6692 200 6/22/2008

45 CA

- BDF

6944 CAJON 34.2281

- 117.4228 100 6/23/2008

46 CA

- LMU

2759 Corral 40.8681

- 120.8825 12,434 6/23/2008

47 CA

- KRN

19301 BENA 35.2725

- 118.6128 120 6/27/2008 6/27/2008

48 CA

- SQF

001356 PIUTE 35.4308

- 118.4011 37,026 6/28/2008 8/31/2008

49 CA

- KNF

003204 No Mans 41.7219

- 123.5325 200 6/30/2008 7/6/2008

50 CA

- LPF

1778 Gap 34.4869

- 119.7828 9,443 7/1/2008

51 CA

- LMU

002934 Dixie 40.8853

- 121.0844 350 7/2/2008 7/4/2008

52 CA

- KNP

0020 Tehipite 36. 9047

- 118.7986 11,596 7/19/2008 12/10/2008

53 CA

- TCU

006881 FRENCH 37.9767

- 120.4808 102 7/22/2008 7/26/2008

54 CA

- KNF

003624 Panther 41.5919

- 123.4308 72,344 7/22/2008

55 CA

- MMU

009779 Telegraph 37.5675

- 119.9969 34,091 7/25/2008

56 CA

- TCU

70 33 Serpentine 37.8089

- 120.3014 162 7/26/2008 7/28/2008

57 CA

- PNF

000784 RICH 40.0114

- 121.1836 6,112 7/29/2008 12/1/2008

5 8 CA

- BTU

9395 Craig 39.5667

- 121.3669 2,001 8/3/2008 8/22/2008

59 CA

- INF

000656 SHERWIN 37.6106

- 118.9403 347 8/3/2008

60 CA

- LPF

- Santa Lucia 34.9678

- 120.1297 244 8/15/2008 9/2/2008

### - 10

-

Map

Number Incident

Number Incident Name Latitude Longitude Size (acres) Star t Date Controlled

Date

002250 Lightning Complex

61 CA

- BNP

0437 Jack 41.8267

- 121.5594 6, 900 8/17/2008

62 CA

- KNF

004096 Slinkard 41.8164

- 123.1653 374 8/17/2008

63 CA

- FKU

009403 Avenal 35.9639

- 120.1078 946 8/19/2008 8/20/2008

64 CA

- SHU

006888 Lake 40.6031

- 122.3819 110 8/26/2008 8/30/2008

65 CA

- SHU

6922 Olinda 40.4122

- 122.3450 186 8/27/2008 8/30/2008

66 CA

- SHF

1949 ELMORE 40.8450

- 122.3633 343 9/7/2008

67 CA

- SHF

1944 GULCH 40.3667

- 122.9350 2,847 9/7/2008



### The National Oceanic and Atmospheric Administration‟s (NOAA) descriptive text narrative for

smoke/dust observed in sa tellite imagery describes dense smoke affecting northern California during this time period. S atellite images as well as numerous news reports and health advisories discussing smoke from the fires were submitted as part of CARB‟s package. 10



### Given this e vidence and the information presented in sections five and six below, we can reasonably conclude that the event in question had the potential to affect air quality.

4.2 Not Reasonably Controllable or Preventable

Pursuant to 40 CFR § 50.14(c)(3), a sta te that is requesting exclusion of data affected by an exceptional event must submit a demonstration to EPA to justify the exclusion. One of the justification criteria is a showing that the event was “not reasonably controllable or preventable.” A determin ation of whether a particular event wa s reasonably controllable or preventable depend s on the specific facts

and circumstances surrounding the event. T herefore , EPA address es this and other criteri a of the exceptional events rule on a case by case basis. 11



### .

The Exceptional Events Rule defines a wildfire as an unplanned, unwanted wildland fire “such as fires caused by lightning...” 12 

### The Summer 2008 California fires were caused by lightning 13 

### and therefore qualify as a wildfires.

We conclude that CARB has demonstrated that the events in question were unplanned wildfires ignited by uncontrollable natural events, and were not reasonably controllable or preventable.

4.3 Natural Event

The Exceptional Events Rule states that “both wildfires and wildland fire use fires fall within the meaning of „natural events‟ as that term is used in CAA § 319. Therefore, ambient particulate matter

10 August NED, Appendix C, Appendix F, and Appendix G.

11 72 FR 13560, 1356 4

12 72 FR 13560, 13566

13 August NED, Appendix G.

### - 11

-

and ozone concentrations due to smoke from a wildland fire will be considered for treatment as an exceptional event if the fire is determined to be either a wildfire or wildland fire use fire.” 14



### CARB asserts that the exceedances were a direct result of the lightning

- ignited June and July wildfires. News reports submitted as part of CARB‟s package confirm that the fires were a resul t of lightning

strikes. 15 

### The events therefore qualify as natural events.



## 5. 0 Clear Causal Relationship

Section 319 of the CAA and 40 CFR § 50.14(c)(3)(iii) require the State to demonstrate that there is a clear causal relationship between the measuremen t under consideration and the event that is claimed to have affected air quality in the area.

As shown in Figure 2 and Table 2 above, a number of fires were ignited primarily along California‟s

northern coast on June 20 th 

### . Over the following days and w eeks, new fires s tarted further inland. Figure 3 shows the location of the Redding, Quincy, and Portola PM 2.5 

### monitors and the location of some of the fires that ignited between June 20

– July 23, 2008.

Figure 3 : Wildfires Ignited June 20

– July 23, 20 08 near the Redding, Portola, and Quincy PM 2.5 

### monitors.

PM 2.5 

### Monitor Icons: 1 = Redding monitor; 2 = Quincy monitor; 3 = Portola monitor

Fire Icons: Dark Purple target

– Fires started 6/20/2008; Light Purple target

– Fires started 6/21/2008;

Pink ta rget

– Fires started 6/22/2008; Orange target

– Fires started 6/23/2008; Yellow target

– Fires started 7/2/2008.

14 72 FR 135660, 13566

15 August NED , Appendix G.

### - 12

-

Wildfire smoke is a mixture of gas and particulate matter, and can adversely affect air quality. The

PM 2.5 

### FRM monitors at Portola and Quinc y sampled every three days in the summer of 2008. The Redding monitor sampled once every six days. As shown in Figure 4 , Portola, Quincy, and Redding began recording elevated PM 2.5 

### concentrations on June 23 and measured lower concentrations by July
26, 2 008. This is consistent with the fires starting June 20, 2008 and containment by July 29, 2008.

Figure 4 : PM 2.5 

### concentrations recorded at Redding, Portola, and Quincy

, June

– August 2008.

The National Oceanic and Atmospheric Administration‟s (NOAA ) descriptive text narrative for smoke/dust observed in satellite imagery describes dense smoke affecting northern California on June 23, 2008. The June 26, 2008 narrative describes a large mass of smoke covering much of California extending north. North ern California is described as being covered by heavy, dense smoke on July

11 th 

### , and moderate to dense smoke on July 19 th 

### . Finally, on July 23 rd 

### the northern third of California is described as covered with moderately dense to dense smoke from the wildfir es. 16 

### Satellite images taken by NOAA‟s Geostationary Operational Environmental Satellite (GOES) server also show what appear to be smoke plumes disseminating over Shasta and Plumas Counties. The June 23, 2008 satellite image is included below. Additional satellite images as well as numerous news reports and health advisories discussing smoke from the fires were submitted as part of CARB‟s package. 17

16 August NED, Appendix E.

17 August NED, Appendix C , Appendix F, and Appendix G

.

### - 13

-

Figure 5. NOAA Satellite Image, June 23, 2008.

Due to the area‟s hill and valley terrain, air masse s impacting one valley may not impact another neighboring valley

. According to CARB‟s submittal, t he Plumas County, Portola monitor sits at an elevation of about 4,895 feet. It is located in a valley, surrounded by hilly terrain . The Plumas County, Quin cy monitor is also in a small valley, and is sited at an elevation of approximately 3,422

feet

. The Shasta County, Redding monitor is located between the Cascades and the Trinity Alps, at approximately 560 feet. 18



### CARB‟s January 26, 2010 supplemental information provided hourly wind vector and streamlines for Northern California on June 23, June 26, and July 11, 19, and 23. These show downslope winds moving air down through the valleys.

Limited speciation data was available at Portola during the pe riod under review; no speciation data was available from Redding or Quincy. Speciated levoglucosan data, used to indicate wood smoke, was

available at Portola on a once

- every

- six

- days schedule in 2007 and 2008. Some additional samples

were also collected at the monitoring agency‟s discretion

. Elevated concentrations were measured in June and July 2008, offering further support that smoke from forest fires was affecting this part of California. (See Table 3.)

18 January 26 Natural Events Documentation ( NED ), p . 5

### - 14

-

Table 3 . Levoglucosan Levels, Portola

- S ummer 2007 and 2008

Month Day 2007 24

- hour Concentration ( 

### μg/m 3 ) 2008 24

- hour Concentration ( 

### μg/m 3 )

June 05 0.01 0.01

June 11 0.01 0.01

June 17 0.01 0.01

June 23 0.01 1.00

June 26 0.01

-

June 29

- 0.32

July 05 0.01 0.26

July 08

- 0.06

July 11 0.0 1

- July 17 0.01 0.01

July 23 0.01 1.40

July 29 0.01 0.01

Aug 04 0.01 0.01

Aug 07 0.01

- Aug 10

- 0.01

Aug 16 0.01 0.01

Aug 19

- 0.01

Aug 22 0.01

- Aug 28 0.01 0.01



### CARB supplied additional wood burning speciation information for Portola. Figu re 6 shows wood burning markers levoglucosan, galactosan, and mannosan

. The figure compares levels measured at Portola from June 23 through July 23, 2008 to the summer average levels.

Figure 6. Wood Burning Markers (Levoglucosan, Galactosan, Mannosan) a t Portola during the Summer 2008 Wildfires, compared to Summer Average.

### - 15

-

Speciation data indicates wood smoke affected the Portola monitor between June 23 and July 23. Satellite images and news reports indicate that smoke from numerous fires was impact ing Shasta and Plumas Counties between June 23 and July 23, 2008. 19 

### Monitored values at Portola, Quincy, and Redding indicate increased concentrations consistent with known fire activity. Taken together, the evidence indicates a clear causal relationship between the measurements under consideration and the

wildfires.



## 6.0 Concentrations in Excess of Normal Historical Fluctuations

Pursuant to 40 CFR § 50.14(c)(3)(iii)(C), the demonstration must show that “the event is associated

with a measured concentr ation in excess of normal historical fluctuations.” There is no “bright line” or specific threshold test for this requirement, but concentrations in the high percentiles can provide supporting evidence. 20



### PM 2.5 

### levels in Plumas and Shasta County vary by s eason. Use of woodburning stoves results in higher wintertime concentrations, while summertime PM 2.5 

### levels in Plumas and Shasta Counties typically fall between 0

- 10 μg/m 3 

### . (See Figures 7, 8 and 9.)

For 2000

- 2008, these three monitors have a number o f summertime fire exceptional events flags

entered into the AQS database. From 2000 to 2008, the highest, non

- flagged summer value monitored at Portola was 17.0 μg/ m 3 

### . The June 23, June 26, July 11, and July 23, 2008 values are all more than

twice this m aximum concentration. If one considers both flagged and non

- flagged data, these four days fall within or above the 98 th 

### percentile (see Table 4), and are four of the five highest summer

values recorded at Portola from 2000

- 2008. As shown in Table 4 and F igure 7, values during the four Portola days in question far exceed the normal range of values observed during the summer months in

Portola.

Table 4. Portola Monitor: Highest PM 2.5 concentrations , Summers (Jun

- Aug) 2000

- 2008.

Date PM 2.5 concentration
( 

### μg/m 3 ) Data Percentile AQS flag

June 26, 2008 113.5 100% rt July 23, 2008 68.6 100 % rt
July 11, 2008 56 99 % rt

Aug 22, 2000 43 99 % e

June 23, 2008 41.2 98 % rt
July 8, 2007 41 9 8% e

June 29, 2008 31.5 97% rt

June 17, 2000 17 97 % none

rt = Wildfire

- U.S.; e = Forest Fire *Uses Parameter Occurrence Code (POC) 07 data for Jun

- Aug 2007; uses POC01 data for all other years. No

2002 data available for Portola.

19 August NED, Appendix C, Appendix E, Appendix G.

20 Exceptional Events Rulemaking (EER) Preamble, 72 FR 13569

### - 16

-

Figure 7. Distribution of Summer ( June

- August ) PM 2.5 

### FRM Concentrations at Portola, 2000

- 2008.

*Uses POC 0 7 data for Jun

- Aug 2007; uses POC 0 1 data for all other years. No 2002 data available.



### The highest, non

- flagged summer value monitored at Quincy from 2000 to 2008 was 16.0 μg/ m 3 

### . At 142.2 and 133 μg/m 3 

### , respectively, the June 23, 2008 and July 19, 2008 values are well above this maximum concentration. If one considers both flagged and non

- flagged data, these two days fall

within the 100 th 

### percentile (see Table 5). These days are the highest recorded at Qu incy over the past

ni ne summers . Values during the two Quincy days in question far exceed the normal range of values observed during the summer months in Quincy. (See Table 5 and Figure 8.)

Table 5. Quincy Monitor: Highest PM 2.5 concentrations , Summers (Jun

- Aug) 2000

- 2 008.

Date PM 2.5 concentration ( 

### μg/m 3 ) Data Percentile AQS flag

June 23, 2008 142.2 100% rt
July 19, 2008 133 100% rt
July 11, 2008 85.5 99% rt

June 26, 2008 80.7 99% rt
July 8, 2008 54.3 98% rt
July 26, 2008 29.3 98% rt

June 28, 2006 26 98% e July 8, 2007 25 97% e
Aug 21, 2002 18 97% e
Aug 1, 2002 17 96% e

June 14, 2008 16 96% none

rt = Wildfire

- U.S; e = Forest Fire

95%

Other Flagged

Fire Events

Flagged

Summer 2008 Events

Under Review

### - 17

-

Figure 8. Distribution of Summer (June

– August) PM 2.5 

### FRM Concentrations at Quincy, 2000

- 2008.

From 2000 to 2 008, the highest, non

- flagged summer value monitored at Redding was 38.0 μg/ m 3



### . The Ju ly 23, 2008 and June 23 , 2008 values of 200.2 and 97.1 μg/ m 3 

### far exceed this maximum concentration. If one considers both flagged and non

- flagged data, these are the tw o highest days recorded at Redding over the past nine summers, and fall within the 99 th 

### and 100 th 

### percentile (see Table 6). As shown in Table 6 and Figure 9, values during the two days in question far exceed the normal range of values observed during the summer months in Redding.

Table 6. Redding Monitor: Highest PM 2.5 concentrations , Summers (Jun

- Aug) 2000

- 2008.

Date PM 2.5 concentration ( 

### μg/m 3 ) Data Percentile AQS flag

July 23, 2008 200.2 100% rt

June 23, 2008 97.1 99% rt

June 29, 2008 92.4 98% rt
July 17, 2008 54.8 98% rt
July 5, 2008 48.3 97% rt

Aug 18, 2002 38 96% none

rt = Wildfire

- U.S. Flagged

Summer 2008 Events

Under Review

Other Flagged

Fire Events 95%

### - 18

-

Figure 9. Distribution of Summer (June

– August) PM 2.5 

### FRM Concentrations at Redding, 2000

- 2008.

These values are evidence that the summer 2008 concentrations under review at Portola, Quincy, and Redding are in excess of normal historical fluctuations and are clear outliers for their respective

monitors.



## 7.0 No Exceedance But For the Event

Pursuant to 40 CFR §50.14(c)(3)(iii)(D), t he demonstration must show that “there would have been no exceedance or violation but for the event.” The weight of evidence in a demonstration does not require a precise estimate of the estimated air quality impact from the event

, 21 

### though that could be u seful. Concentrations on days with similar emissions but without the influence of the event are rough evidence of what the concentration on the event day would have been but for the event. Comparison to otherwise similar days may provide one kind of evid ence in the demonstration that the exceedance

would not have occurred but for the event.

The following three figures show summer concentrations for Portola, Quincy, and Redding, measured

from 2000

- 2008. Although Portola did not measure PM 2.5 

### during the s ummer of 2002, all other years are represented for each monitor.

Meteorological conditions during this nine year period would be expected to include multiple days with meteorology similar to conditions seen on the days under review. The two 2008 values under review at Quincy are well above values recorded at any other time during summers 2000

- 2008. (See Figure 10.) Except for other summer 2008 days also associated with the 2008 wildfires, the two

21 EER Preamble 72 FR 23570 Flagged

Summer 2008 Events

Under Review

Other Flagged

Fire Events 95%

### - 19

-

Redding values under review far exceed any summer conce ntrations measured 2000

- 2008. (See Figure 11.) 2008 values at Portola are also well above recorded values, with the exception of one day in 2000 and one day in 2007, both of which are flagged in AQS as fire events. (See Figure 12.)

Figure 10. Quincy P M 2.5 

### Concentrations: June

– August, 2000

- 2008.

Figure 11. Redding PM 2.5 

### Concentrations: June

– August, 2000

- 2008.

July 23, 200 8 Event

Under Review June 23, 2008 Event

Under Review July 19, 2008

Event Under

Review

June 23, 2008

Event Under

Review

### - 20

-

Figure 12. Portola PM 2.5 

### Concentrations: June

– August, 2000

- 2008.

The presence and extent of the wildfires, coupled with the speciation data, satellite images, news reports discussed in Section 5, and the uniqueness of the values over the past nine summers supports the conclusion that there would not have been exceedances on the days in question but for the

wildfires

.



## 8.0 Procedural Requirements

The EER at 40 CFR §50.14(c) requires that data claimed to be due to an exceptional event must be flagged in the AQS database, that an initial description of the event be provided to EPA by July 1 of the year following the e vent, and the State must submit a demonstration to EPA within three years of

the event.

CARB flagged the events in AQS in accordance with 40 CFR §50.14 . On August 28, 2009, CARB submitted their package for the Summer 2008 PM 2.5 

### events. CARB sent addit ional clarification to EPA via email on January 19, 2010, and January 26, 2010.

40 CFR §50.14(c)(3)(i) also requires notice and opportunity for public comment. 40 CFR §50.14(c)(3)(i) requires that any public comments be submitted along with the demonstra tions. CARB public noticed the Summer 2008 PM 2.5 

### Events package beginning July 20,2009. The package was

June 23, 2008 & June 26, 2008

Events Under

Review July 11, 2008 & July 23, 2008 Events

Under Review

### - 21

-

posted on the CARB website, and air districts and public listserv recipients were notified. No public

comments were received. 22



### Numerous health and smoke advisories issued in response to the summer 2008 fires are included as Appendix F in CARB‟s August 28, 2009 submittal.



## 9.0 Conclusion

Documentation submitted by CARB claims that smoke from the summer 2008 wildfires caused

exceedances of the 24

- hour PM 2.5 

### NAAQS at numerous monitoring stations. This package reviews exceedances at the Portola monitor on June 23, June 26, July 11, and July 23, 2008, exceedances at the Quincy monitor on June 23 and July 19, 2008, and exceedances at the Redding monit or on June 23 and July 23, 2008. All values under review fall above their respective site‟s 95 th 

### percentile observed during summer months (June

– August), 2000

- 2008. The values far exceed the expected range of concentrations for unflagged days and fall i nto or above the 98 th 

### percentile when considering all data (flagged and unflagged). Speciation data collected at Portola shows evidence of forest fire contributions, and news reports, satellite imagery, and wind field modeling indicate smoke from the

wild fires was affecting air quality in Plumas and Shasta Counties. The information and analyses presented in this package and in CARB‟s submittal documents do not represent the entire suite of possible evidence for exceptional event packages. For other types of events and other pollutants, additional or alternate evidence may be necessary to make an exceptional events determination. In this particular instance, however, given that the events are wildfires affecting 24

- hour PM 2.5 

### concentrations, the weight of evidence is sufficient to satisfy the EER criteria

. EPA concurrence is given to the

aforementioned Summer 2008 PM 2.5 

### exceptional event flags for the Portola, Quincy, and Redding

monitors.



## 10 .0 Citation of Exceptional Event Request Documentation

Aug ust NED August 28, 2009 Natural Event Documentation “PM2.5 and PM10 Natural Event Document: Summer 2008 Northern California Wildfires, June/July/August 2008,” California Air Resources Board, August 28, 2009, with attachments.

Letter from Karen Magliano, Air Resources Board, to Matthew Lakin, U.S. Environmental Protection Agency Region 9, August 28, 2009 requesting exclusion of Summer 2008 exceedances, with enclosures: August NED.

January 19 NED January 19, 2010 Natural Event Documentation

“2008 Northern California Wildfires,” California Air Resources Board, January 19, 2010.

January 26 NED January 26, 2010 Natural Event Documentation “Wind Fields in Northern California During the 2008 Wild Fires,” California Air Resources Board, January 26, 2010.

22 January 19 NED, p. 1.