### Linda S. Adams

Secretary for

Environmental Protection

The energy challenge facing California is real. Ev ery Californian needs to take immediate action to r educe energy consumption. For a list of simple ways you can reduce demand and cut your energy costs, see our website: http://www.arb.ca.gov

. 

## California Environmental Protection Agency

Printed on Recycled Paper 

# Air Resources Board

Mary D. Nichols, Chairman

1001 I Street • P.O. Box 2815 Sacramento, California 95812 • www.arb.ca.gov Arnold Schwarzenegger

Governor



## March 11, 2009

Ms. Laura Yoshii Acting Regional Administrator U.S. Environmental Protection Agency Region 9

75 Hawthorne Street
San Francisco, California 94105

Dear Ms. Yoshii:

We are transmitting our recommendations for area de signations and boundaries under the revised federal 8-hour ozone standard, as requi red under the Federal Clean Air Act.

Ozone Nonattainment Areas

We base our recommendations on ambient ozone concen trations measured from 2006 through 2008 by 180 Federal Reference Method (FRM) monitors located throughout California. The Air Resources Board’s (ARB) recomm endation is that the U.S. Environmental Protection Agency (U.S. EPA) des ignate twenty-one areas as

nonattainment for the revised ozone standard of 0.0 75 parts per million. Enclosure 1, included with this letter, lists the proposed nonat tainment areas, which include all fifteen areas currently designated nonattainment for the 0. 08 parts per million ozone standard, along with six new or expanded areas.

We also recommend that U.S. EPA designate twelve ar eas as attainment, where air quality data are sufficient to determine that they meet the federal standard. Finally, five should be deemed unclassifiable, where air quality data are insufficient to make a

determination.

Nonattainment Area Boundaries

Regarding nonattainment area boundaries, ARB makes the following recommendations:

• Retain the existing nonattainment area boundaries for the fifteen areas that are currently designated as nonattainment for ozone.

## Ms. Laura Yoshii

March 11, 2009 Page 2

• Expand the Eastern Kern County nonattainment area to include Indian Wells Valley and the town of Ridgecrest.

• Establish our recommended nonattainment boundaries for new rural transport areas. These areas are Southern Inyo County, North east San Bernardino County, Eastern San Luis Obispo County, the high el evation site on the Tuscan Buttes and the specified portion of Pinnacles Natio nal Monument located in San Benito County.

Enclosures

We include the following materials in this package:

• Recommended nonattainment/attainment/unclassifiabl e areas (Enclosure 1).

• Staff Report (Enclosure 2).

• Information supporting recommendations for nonatta inment areas (Enclosure 3).

• Boundary descriptions (Enclosure 4).

• 2006-2008 data for all of California’s ozone monit oring sites (Enclosure 5).

Classification Process

We are completing a technical evaluation of the how well the classification scheme used

for the current 8-hour ozone standard worked for Ca lifornia. Upon completion we will
share this information, and want to work with U.S. EPA on potential changes that would improve the ozone classification process.

Please feel free to contact me at (916) 445-4383 if you have any questions regarding these recommendations, or have your staff contact M s. Karen Magliano, Chief, Air Quality Data Branch, at (916) 322-7137.

Sincerely,

/s/

James N. Goldstene

Executive officer

Enclosures

## Ms. Laura Yoshii

March 11, 2009 Page 3

cc: Ms. Deborah Jordan, Director U.S. Environmental Protection Agency Air Division – Region 9

75 Hawthorne Street
San Francisco, California 94105

Ms. Amy Zimpfer

Assistant Director U.S. Environmental Protection Agency Air Division – Region 9

75 Hawthorne Street
San Francisco, California 94105

Mr. Barry Wallerstein

Air Pollution Control Officer South Coast Air Quality Management District 21855 E. Copley Drive
Diamond Bar, California 91765-4182

Mr. Michael J. Villegas

Air Pollution Control Officer Ventura County Air Pollution Control District 669 County Square Drive, 2 nd 

## Floor
Ventura, California 93003-5417

Ms. Rosa Abreu Acting Air Pollution Control Officer San Diego County Air Pollution Control District

10124 Old Grove Road San Diego, California 92131-1649

Mr. Larry Allen

Air Pollution Control Officer San Luis Obispo Air Pollution Control District

3433 Roberto Court San Luis Obispo, California 93401-7126

Continued next page.

## Ms. Laura Yoshii

March 11, 2009 Page 4

cc: (continued)

Mr. Seyed Sadredin

Air Pollution Control Officer San Joaquin Valley Air Pollution Control District 1990 East Gettysburg
Fresno, California 93726

Mr. Larry Greene

Air Pollution Control Officer Sacramento Metro Air Quality Management District

777 12 th 

## Street, Third Floor
Sacramento, California 95814-1908

Ms. Marcella McTaggart

Air Pollution Control Officer El Dorado County Air Quality Management District 2850 Fairlane Court, Building C
Placerville, California 95667-4100

Mr. Tom Christofk

Air Pollution Control Officer Placer County Air Pollution Control District 3091 County Center Drive, Suite 240
Auburn, California 95603

Mr. Mat Ehrhardt

Air Pollution Control Officer Yolo-Solano Air Quality Management District
1947 Galileo Court, Suite 103
Davis, California 95616-4882

Mr. Dave Valler

Air Pollution Control Officer Feather River Air Quality Management District

938 14 th 

## Street Marysville, California 95901-4149

Continued next page.

## Ms. Laura Yoshii

March 11, 2009 Page 5

cc: (continued)

Dr. Charles Mosher

Air Pollution Control Officer Mariposa County Air Pollution Control District

P.O. Box 5 Mariposa, California 95338

Mr. Gary Caseri

Air Pollution Control Officer Tuolumne County Air Pollution Control District

2 South Green Street
Sonora, California 95370-4618

Mr. Jim Harris

Air Pollution Control Officer Amador County Air Pollution Control District
665 New York Ranch Road, #4
Jackson, California 95642

Mr. Lakhmir Grewal

Air Pollution Control Officer Calaveras County Air Pollution Control District

Government Center

891 Mountain Ranch Road
San Andreas, California 95249-9709

Mr. Doug Quetin

Air Pollution Control Officer Monterey Bay Unified Air Pollution Control District

24580 Silver Cloud Court Monterey, California 93940-6536

Mr. Jack Broadbent

Air Pollution Control Officer Bay Area Air Quality Management District

939 Ellis Street
San Francisco, California 94109-7799

Continued next page.

## Ms. Laura Yoshii

March 11, 2009 Page 6

cc: (continued)

Mr. W. James Wagoner

Air Pollution Control Officer Butte County Air Quality Management District
2525 Dominic Drive, Suite J
Chico, California 95928-7184

Mr. Alan Abbs

Air Pollution Control Officer Tehama County Air Pollution Control District

1750 Walnut Street
Red Bluff, California 96080-0038

Mr. Brad Poiriez

Air Pollution Control Officer Imperial County Air Pollution Control District

150 South 9 th 

## Street
El Centro, California 92243-2801

Mr. Eldon Heaston

Executive Director Antelope Valley Air Quality Management District
43301 Division Street, Suite 206
Lancaster, California 93535-4649

Mr. Ted Schade

Air Pollution Control Officer

Great Basin Unified Air Pollution Control District
157 Short Street, Suite 6 Bishop, California 93514-3537

Mr. David L. Jones

Air Pollution Control Officer Kern County Air Pollution Control District
2700 M Street, Suite 302
Bakersfield, California 93301-2370

Continued next page.

## Ms. Laura Yoshii

March 11, 2009 Page 7

cc: (continued)

Mr. Eldon Heaston

Executive Director Mojave Desert Air Quality Management District

14306 Park Avenue
Victorville, California 92392-2310

Mr. Russ Mull

Air Pollution Control Officer Shasta County Air Quality Management District
1855 Placer Street, Suite 101 Redding, California 96001-1759

Ms. Gretchen Bennitt

Air Pollution Control Officer Northern Sierra Air Quality Management District
200 Litton Drive, Suite 320 Grass Valley, California 95945-2509

## - 1

- ENCLOSURE 1

Recommended California Nonattainment Areas for the Federal 8

- Hour O zone Standard

Based on 2006

- 2008 Ozone Air Quality Data

Nonattainment Area Design

Value 1



## (ppm) Area Included

Northeast San Bernardino County 0.080 Remainder of th e Mojave Desert portion of

San Bernardino County outside the Western Mojave ozone nonattainment area

Southern Inyo County 0.081 Inyo County portions of federal h ydrologic units 16060015, 18090202, 18090203, 18090204, and

18090205 Eastern San Luis Obisp o County 0.0 84 Eastern San Luis Obispo County

Pinnacles 0.079 San Benito County portion of Pinnacles National

Monument New

Areas

Tuscan Buttes 0.085 Tuscan Buttes in Tehama County above 1800’ Expanded

Area Eastern Kern County 0.086 Mojave Desert Air Basin p or tion of Kern County

, including Indian Wells Valley

South Coast Air Basin 0.119 Western Los Angeles (including Catalina and San Clemente Islands), Orange, southwestern
San Bernardino, and western Riverside counties

San Joaquin Valley 0.1 08 San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare, and western Kern counties

Sacramento Metro Area 0.102 Sacramento, Yolo, eastern Solano, southern Sutter, and western portions of El Dorado and

Placer counties

San Francisco Bay Area 0. 081 Marin, southern Sonoma, Napa, western Solano,
Contra Costa, Alameda, Santa Clara, San
Francisco, and San Mateo counties

Ventura County 0.088 Continental portion of Ventura County (excludes Anacapa and San Nicolas islands) Western Mojave Desert 0.10 4 Central San Bernardino County
Antelope Valley 0.094 Northeastern Los Angeles County Coachella Valley 0.097 Central Riverside County San Diego County 0.092 San Diego County Imperial County 0.082 Imperial County

Sutter Buttes 0.085 Sutter Buttes in Sutter County above 2000’

Central Mountain Counties 0.089 Amador and Calaveras counties

Southern Mountain Counties 0.088 Tuolumne and Mariposa counties

Western Nevada County 0.091 Portion of Nevada County west of the crest of the

Sierra Nevada Continu ing

Areas

Butte County 0.085 Butte County

1 

### The design value is the 3

- year average (2006

- 2008 data) of the annual fourth highest 8

- hour ozone concentration at the highest monitor (if greater than 0.075 ppm = nonattainment; if less
than or equal to 0.075 = attainmen t). 2008 data are preliminary.

## - 2

- Recommended California Attainment Areas for the

Federal 8

- Hour Ozone Standard

B ased on 2006

- 2008 Ozone Air Quality Data

A ttainment Area Design

Value 1



## (ppm) Area Included

North Coast Air Basin 0.058 Del Norte, Humboldt, Mendocino, and Trinity

counties and the North Coast Air Basin portion of Sonoma County Shasta County 0.0 73 Shasta County

Tehama County 0.075 Portion of Tehama County outside Tuscan

Buttes area Glenn County 0.065 Glenn Count y 2



## Colusa County 0.069 Colu sa County

Sutter and Yuba Counties 0.072 Yuba County and portion of Sutter County

outside Sacramento Metro A rea and Sutter

Buttes area Lake County 0.062 Lake County

Lake Tahoe Air Basin 0.070 Lake Tahoe Air Basin portions of El Dorado

and Placer countie s

North Central Coast Air

Basin 0.069 Monterey County, Santa Cruz County,

San Benito County outside Pinnacles National Monument boundary

Santa Barbara County 0.073 Continental portion of Santa Barbara County (excludes San Miguel, Santa Barbara, Santa

Cru z, and Santa Rosa islands)
Western San Luis Obispo County 0.06 8 Portion of County west of Eastern San Luis Obispo area

Eastern Riverside County 0.063 Portion of Riverside County in Mojave Desert

Air Basin

1 

### The design value is the 3

- year average (2006

- 2 008 data) of the annual fourth highest 8

- hour ozone concentration at the highest monitor (if greater than 0.075 ppm = nonattainment; if less than or equal to 0.075 = attainment). 2008 data are preliminary.

2 

### Reflects combined data from 2 monitoring sites.

## - 3

- Recommended California Unclassifiable Areas

for the Federal 8

- Hour Ozone Standard

Unclassifiable Area Area Included

Great Basin Valleys Air Basin Alpine County, Mono County, portion of Inyo County outside Southern Inyo County

nonattainment area

Northern Mountain Counties Plumas and Sierra counties

Northern Channel Islands T he islands located in the South Central Coast Air Basin, including Anacapa, San Miguel,

San Nicolas, Santa Barbara, Santa Cruz, and

Santa Rosa

Eastern Nevada County Portio n of Nevada County east of the crest of the

Sierra Nevada mountains

Northeast Plateau Air Basin Lassen, Modoc, and Siskiyou counties

# State of California

AIR RESOURCES BOARD

Revised : March 3

, 200 9 

# RECOMMENDED

AREA D ESIGN

ATIONS

FOR THE 2008

FEDERAL

8

- HOUR OZONE STANDARD

STAFF REPORT

California Environmental Protection Agency



# Air Resources Board

## i TABLE OF CONTENTS

Page

BACKGROUND

................................ ................................ ................................ ........................ 1

OZONE AIR QUALITY

................................ ................................ ................................ ............ 2

RECOMMENDED AREA DESIGNATION S

................................ ................................ ......... 2

New Nonattainment Areas

................................ ................................ ................................ 6 Northeast San Bernardino County

................................ ................................ ............. 6 Southern Inyo County

................................ ................................ ................................ .. 7

Pinnacles National Monument

................................ ................................ ................... 8 San Luis Obispo County

................................ ................................ ............................. 9

Tuscan Buttes

................................ ................................ ................................ ............... 9 Expanded Nonattainment Area

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

Eastern Kern County

................................ ................................ ................................ . 10 Existing Nonattainment Areas

................................ ................................ ........................ 1 1

South Coast Air Basin

................................ ................................ ............................... 1 1 San Joaquin Valley

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

Sacramento Metro

................................ ................................ ................................ ...... 11 San Francisco Bay Area

................................ ................................ ........................... 11 Ventura County

................................ ................................ ................................ ........... 11 Western Mojave Desert

................................ ................................ ............................. 1 2 Antelope Valley

................................ ................................ ................................ ........... 12 Coachella Valley

................................ ................................ ................................ ......... 12 San Diego County

................................ ................................ ................................ ...... 12 Imperial County

................................ ................................ ................................ ........... 12

Sutter Buttes

................................ ................................ ................................ ............... 12

Central Mountain Counties

................................ ................................ ....................... 12

Southern Mountain Counties

................................ ................................ .................... 1 3 Western Nevada County

................................ ................................ ........................... 1 3 Butte County

................................ ................................ ................................ ............... 1 3

Attainment Areas

................................ ................................ ................................ .............. 13

Shasta County

................................ ................................ ................................ ............ 1 3 Eastern Riverside County

................................ ................................ ......................... 14

Other Areas

................................ ................................ ................................ ................. 14

Unclassifiable Areas

................................ ................................ ................................ ........ 16

## ii LIST OF TABLES AND FIGURES

Page

FIGURE 1: Recommended Area Designations for the Federal 8

- Hour

Ozone Standard

................................ ................................ ............................... 4

TABLE 1: Recommended California Nonattainment Areas for the Federal 8

- Hour

Ozone Standard Based on 2006

- 2008 Ozone Air Quality Data

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

TABLE 2: Recommended California Attainment Areas for the Federal 8

- Hour

Ozone Standard Based on 2006

- 2008 Ozone Air Quality Data

............. 1 5

TABLE 3: Recommended California Unclassifiable Areas for the Federal

8

- Hour Ozone Standard

................................ ................................ ................ 1 6

ATTACHMENT A: SUMMARY OF OZONE DATA POTENTIALLY IMPACTED BY

EXCEPTIONAL EVENTS

ATTACHMENT B: 2006

- 2008 FEDERAL 8

- HOUR OZONE DESIGN VALUES

BY SITE

## - 1

-

BACKGROUND

On March 12, 2008, U.S. EPA revis ed the federal 8

- hour average air quality standard for ozone, lowering it from 0.08 parts per million (ppm) to 0.075 ppm. Both the primary and the secondary standard are set at the same level. Under the Clean Air Act, all states, including California, are required to develop

recommendations for area designation s and appropriate boundar ies

. The purpose of this report is to summarize the staff’s technical analyses and area designation recommendations which are due to U.S. EPA by Mar ch 12, 2009.

U.S. EPA then has one year to review these recommendations and will promulgate final designat ions by March 12, 2010. State implementation plans are due three years after the effective date of the final designations, with attainment dates ranging from 2013 to 2030, depending on the severity of the ozone problem.

ARB staff completed analyses to determine appropriate designation areas throughout the State using the criteria outlined in U.S. EPA’s guidance memo
( December 4, 2008, Area Designations for the 2008 Revised Ozone National Ambient Air Quality Standards, Memorandum from Robert J. Meyers, P rincipal Deputy Assistant Administrator, Office of Air and Radiation to Regional Administrators, Regions I

- X ). Determining an area’s designation is based on comparing the design value to the level of the standard. The design value

reflects a three

- year a verage of the 4 th 

## highest 8

- hour concentration. If the design value is 0.076 ppm or greater, it violates the federal standard. The recommendations in this report are based on design values reflecting 2006 through 2008 ozone data. However, ARB anticipate s that U.S. EPA will base the final designations on the most recent data, which will most likely be data
collected during 2007 through 2009.

Under U.S. EPA’s guid ance , air quality data may be excluded from the design

value calculation if they were affec ted by an exceptional event

. An exceptional
event is an event, such as a wildfire, that causes an exceedance that is not
reasonable to control through the regulatory process. During 2007 and 2008, wildfires impacted air quality throughout California. Ho wever, there is only one area in the State, Shasta County, where excluding such data makes a difference between attainment and nonattainment based on the design value for the 2006 through 2008 timeframe. Attachment A to this staff report includes a list o f sites

and dates for Shasta County that we are evaluat ing for identification as exceptional events.

In addition to Shasta County, other areas of California were also adversely impacted by wildfires. In some cases, the fire

- impacted days may advers ely
impact design values, based on the 2007 through 2009 data that we expect

U.S. EPA to use in determining the final area designations. S uch measurements
might also affect an area’s classification with respect to the 0.075 ppm ozone

## - 2

-

standard. ARB and the local districts are still investigating the se impacts, and

will submit documentation to U.S. EPA in accordance with established rules and
regulations.

OZONE AIR QUALITY

ARB maintains a comprehensive network o f federally sanctioned ozone monitors.

T his network comprises nearly 200 monitors, statewide. We are basing our initial

recommendations on ambient ozone concentrations measured during 2006 through 2008 at locations sited and operated in accordance with federal requirements.

Ozone is not dir

ectly emitted, but is formed in the atmosphere via photochemical reactions. Because it takes time for these reactions to occur, high concentrations are often found at downwind locations, sometimes far away from the initial precursor emissions sources. In California, many of these transport

- impacted areas do not have significant emissions sources of their own, and therefore are depend ent

on emissions controls in the upwind region to mitigate their ozone
problem.

Our recommendations for several of Califor nia’s new nonattainment areas
recognize th e importance of transport

. R ecent photochemical modeling completed as part of the planning process for the 0.08 ppm federal 8

- hour ozone

standard showed that many of the State’s downwind transport

- impacted area s

w ill attain the s tandard as a result of upwind emissions controls . The modeling

also showed that because ozone concentrations in the transport

- impacted areas

are generally lo wer , they should attain earlier than the upwind urban areas. This is particularly true for areas located downwind of the South Coast Air Basin. As a

result , o ur recommended ozone nonattainment boundaries recognize these differences in the challenge, and also, differences in the level of control requirements, as well as local planning jurisdictions.

RECOMMENDED AREA DESIGNATIONS

Section 107(d)(1)(A) of the Clean Air Act defines a nonattainment area as any
area that does not meet or that contributes to nearby areas not meeting the ambient air quality standard. U.S. EPA guidance re commends that the Core Based Statistical Area (CBSA) or Combined Statistical Area (CSA), which includes two or more CBSAs, serve as the starting point or “presumptive” boundary for an ozone nonattainment area. When a violating monitor is not

located in a CBSA or CSA, U.S. EPA recommends that the boundary of the county in which the monitor is located serve as the presumptive boundary. In further refining the extent of the boundaries, U.S. EPA recommends that states

evaluate each area on a case

- by

- case basi s, considering nine factors :

## - 3

- • Air quality data

• Emissions data

• Population density and degree of urbanization

• Traffic and commuting patterns

• Growth rates and patterns

• Meteorology

• Geography/topography

• Jurisdictional boundaries

• L evel of control of emission sources

Evaluation of these factors may support nonattainment area boundaries that are either larger or smaller than the presumptive boundary. Although each of our

recommended nonattainment area s is unique, the boundaries emb ody several broad principles:

• For existing 8

- hour ozone nonattainment areas, we retained the same
nonattainment area boundaries, with the exception of expanding one

area

.

• For new nonattainment areas, a single monitor showing violati o n s of

the 8

- hour ozone standard places the area into nonattainment status. While the starting point for a new nonattainment area is generally the county, our consideration of factors outlined in U.S. EPA guidance justified a smaller nonattainment area in m any case s

.

As shown in Figure 1, most of California will be nonattainment for the 8

- hour

ozone standard. We are proposing the State be divided into 21 distinct
nonattainment areas. We are also proposing that 1 2 areas be designated as

attainment. Table 1 presents a summary of the recommended nonattainment areas and corresponding boundaries. Following the figure and table, we discuss

each of the nonattainment area recommendations , followed by a discussion of areas that qualify as attainment and areas that qualify as unclassified

.

## - 4

- 

# FIGURE 1

Recommended Area Designations for the

Federal 8

- Hour Ozone Standard

South Coast

Air Basin Western Mojave Desert San Francisco
Bay Area Sutter Buttes Sacramento Metro Area Western Nevada County

Southern Mountain Counties

San Joaquin Valley

Eastern Kern

Coachella Valley

Imperial County Antelope Valley

San Diego

County Ventura County Tuscan Buttes

Pinnacles

Eastern

San Luis
Obispo County Southern Inyo County

Butte County

Central Mountain Counties

Unclassified

Existing Nonattainment Attainment

Recommend ed New No nattainment 

# N E San Bernardino County

## - 5

- TABLE 1

Recommended California Nonattainment Areas for the Federal 8

- Hour O zone Standard

Based on 2006

- 2008 Ozone Air Quality Data

Nonattainment Area Design

Value 1



## (ppm) Area Included

Northeast San Bernardino County 0.080 Remainder of the Mojave Desert portion of

San Bernardino County outside the Western Mojave ozone nonattainment area

Southern Inyo County 0.081 Inyo County portions of federal h ydrologic units
16060015, 18090202, 18090203, 1809 0204, and

18090205

Pinnacles 0.079 San Benito County portion of Pinnacles National

Monument

Eastern San Luis Obispo County 0.08 4 Eastern San Luis Obispo County New

Areas

Tuscan Buttes 0.085 Tuscan Buttes in Tehama County above 1800’ Expanded

Area Eastern Ker n County 0.086 Mojave Desert Air Basin p ortion of Kern County

, including Indian Wells Valley

South Coast Air Basin 0.119 Western Los Angeles (including Catalina and San Clemente Islands), Orange, southwestern
San Bernardino, and western Riv erside counties

San Joaquin Valley 0.108 San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare, and western Kern counties

Sacramento Metro Area 0.102 Sacramento, Yolo, eastern Solano, southern Sutter, and western portions of El Dorado and

Plac er counties

San Francisco Bay Area 0.081 Marin, southern Sonoma, Napa, western Solano,
Contra Costa, Alameda, Santa Clara, San
Francisco, and San Mateo counties

Ventura County 0.088 Continental portion of Ventura County (excludes Anacapa and San Nicol as islands) Western Mojave Desert 0.104 Central San Bernardino County
Antelope Valley 0.094 Northeastern Los Angeles County Coachella Valley 0.097 Central Riverside County San Diego County 0.092 San Diego County Imperial County 0.082 Imperial Cou nty

Sutter Buttes 0.085 Sutter Buttes in Sutter County above 2000’

Central Mountain Counties 0.089 Amador and Calaveras counties

Southern Mountain Counties 0.088 Tuolumne and Mariposa counties

Western Nevada County 0.091 Portion of Nevada County w est of the crest of the

Sierra Nevada Existing

Areas

Butte County 0.085 Butte County

1 

### The design value is the 3

- year average (2006

- 2008 data) of the annual fourth highest 8

- hour ozone concentration at the highest monitor (if greater than 0.075 ppm = nonattainment; if less
than or equal to 0.075 = attainment). 2008 data are preliminary.

## - 6

-

New Nonattainment Areas

Northeast San Bernardino County

San Bernardino County is the largest county in the nation, compri s ing over 20,000 square miles . Because of its size, it enco mpasses a very diverse landscape. Currently, the central portion of San Bernardino County, located in the Mojave Desert Air Basin, is defined as the Western Mojave Desert (WMD) nonattainment area. While the presumptive boundary for an expanded

nonattainm ent area would include the entire Mojave Desert portion of

San Bernardino County, ARB is recommending the area be designated as two separate areas, based on differences in the nature and severity of the ozone
problems.

With a population of more than 35 0,000 (2006 estimate), t h e WMD portion of

San Bernardino County is adjacent to the South Coast Air Basin. Gi ven its proximity to the South Coast, m ajor highways traveling through the WMD carry significant commuter and truck traffic in and out of the South Coast region. Principal cities in the area include Hesperia, Phelan, Victorville, Apple Valley, and
Twentynine Palms

. Previous transport assessments show that ozone concentrations in the WMD portion of San Bernardino County are impacted by transport fro m the South Coast and San Joaquin Valley air basins , which are the
areas with the highest ozone levels in the state . Along with the transport impact,

there is also a local component to the ozone problem in this area. The design

value for the WMD is 0.104 ppm at the Joshua Tree

- National Monument site.

D esign values for other sites in the area are similar in magnitude , though slightly

lower

.

In contrast

to the WMD, the more remote northeast portion of San Bernardino County is sparsely populated . There are no sizable cities, and the area has few significant emission sources. Because the area lacks significant population centers and emissions sources capable of generating ozone locally, the transport
component is even more important. Furthermore , the de sign value for t his part of

San Bernardino County is 0.080 ppm, which is substantially lower than the WMD
design value.

Although the north east portion of San Bernardino County is contiguous with the
existing WMD nonattainment area and is part of the sam e county, ARB staff is recommending it be defined as a separate nonattainment area. The design value for the WMD portion of San Bernardino County is 30 percent higher than the design value for the northeast portion of the County. Although both areas will rely on controls from u pwind areas to reach attainment, because the magnitude of their problems is so different, the northeast portion of San Bernardino County

should attain the standard in a shorter timeframe. Designating the area
separately would give them a classification consistent with their overall air quality problem and facilitate a more timely attainment finding.

## - 7

-

Southern Inyo County

Inyo County is the second largest count y in California and one of the largest

counties in

the nation. It enc ompasses more than 10 ,000 square miles, from the below sea level floor of Death Valley to the 14,000 foot peaks of the Sierra Nevada. The only long

- term ozone monitor in Inyo County is located at the Death Valley National Monument in southeast Inyo County . The site is operated by the National Park Service and has a design value of 0.081 ppm, which

exceeds the federal standard. Th e area has an extremely low population, with
only 0.22 residents per square mile

, and lacks industrial emissions sources

. Whil e t he presumptive boundary for th e nonattainment area would include all of Inyo Count y, ARB is r ec ommending a smaller nonattainment area because of the diversity of the area’s geography and the nature of the ozone impact

.

Previous studies suggest that o zone concentrations at the Death Valley site are substantially impacted by transport. Wind flow into the southern portion of the County is generally from the southwest to northeast , carrying pollutants and emissions from the highly urbanized South Coast and southern San Joaquin Valley air basins into southern Inyo County

. Although Death Valley is the only monitoring site in southern Inyo County

, data are also collected at the Trona site

in San Bernardino County , just 2 miles south of the Inyo County lin e. The se data

s uggest that exceedances are also likely to occur in the southwest portion o f Inyo County. During 2004 through 2008, about half of the exceedance days at Trona coincide with exceedance days at Death Valley, indicating that the nonattainment area should include the southwest portion of Inyo County, as well as the Death

V alley area.

In addition to the se data , limited 2008 ozone monitoring data are available for a

site at Bishop, in the northern portion of Inyo County. Th e site is operated by the
Bishop Piute Tribe. The Bishop data show several days with concentrations

above the federal 8

- hour standard, but because the data are incomplete , it is not possible to calculate a valid design value for this site and determine if it would

violate the standard. Furthermore, an analysis completed by the Great Basin

Unified Air Pollution Control District (APCD) shows that emissions and pollutants from this area do not likely contribute to the exceedances at Death Valley

.

In determining the appropria te nonattainment area boundary, ARB staff

consulted with the local Great Basin Unified APCD . The recommended boundary for this area is based on federal hydrologic units. Hydrologic units are
based on topography and drainage, similar in many respects to t he way

California’s air basins are defined. Therefore, it is appropriate to use them in defining the nonattainment area boundary, since mountainous terrain affects the transport and mixing depth of pollution. In addition, hydrologic units have been

used previously to define designated areas for ozone . ARB staff recommends the Southern Inyo County ozone nonattainment area comprise the Inyo County

## - 8

-

portion s of federal hydrologic units 16060015, 18090202, 18090203, 18090204,

and 18090205 . These units cove r not only the area s exceeding the standard, but also the areas most heavily impacted by transport from the major upwind urban

areas.

Pinnacles

National Monument

San Benito County is located in California’s north central coast region, just south

of the San Francisco Bay A rea (Bay Area) . Although it is consider ed part of the coastal region, San Benito County is located inland. The federal ozone standard is exceeded at only one site in this area, the Pinnacles National Monument site, with a design value of 0.079 ppm.

With the exception of 2008, the trend in the design value for Pinnacles has been
consistently downward. In fact, the 2006 and 2007 design value s for this site (0.075 ppm and 0.074 ppm, respectively) show attainment. The higher value fo r 2008 likely reflects the impact of wildfires that burned throughout the State during

the summer of 2008 . If the impacted days were removed from consideration, the 2008 design value would be more consistent with values for pr evious years

. However, the a rea would still be nonattainment

. In contrast to Pinnacles, d esign values for sites in the surrounding north central coast region are all well below the level of the standard, ranging from 0.052 ppm to 0.069 ppm.

Pinnacles is an elevated site (1000 fe et) located in an area of complex terrain
within the boundaries of Pinnacles National Monument. Previous transport study

indicates that exceedances measured at Pinnacles can be overwhelmingly impacted by transport aloft from the Bay Area. Although t he Sa n Francisco Bay

Area d oes not yet attain the standard , design values for Bay Area sites have decreased since the early 2000s, similar to those for Pinnacles. As emissions in
the Bay Area continue to decrease, ozone concentrations in downwind areas

such a s Pinnacles will also improve.

Because exceedances in San Benito County are measured only at Pinnacles and nowhere else in the local area, ARB recommends limiting the nonattainment

area . The ozone problem at Pinnacles is attributable to transport from the Bay

Area , which is already designated as nonattainment. Designating Pinnacles as nonattainment, as well, would adequately reflect the impact region for th e upwind

urban area. Specifically, ARB recommends limiting the nonattainment area to that porti on of Pinnacles National Monument located within San Benito County.
Using the Monument boundary would provide for an easily identifiable

nonattainment area

.

## - 9

-

Eastern San Luis Obispo County

San Luis Obispo County is located in California’s south centra l coast region and encompasses coastal, as well as inland areas. The design value for the County

is 0.08 4 ppm, measured at the Carrizo Plains School

- 9640 Carrizo site in the eastern part of the County . This site is located in a populated area and was

ori ginally sited to provide information on transport impacts from the San Joaquin Valley. The design value for a second inland , eastern County site, Red Hills , is

also above the standard at a level of 0.08 8 ppm , but only two years of data are

available . In contrast to Carrizo Plains , the Red Hills site is located in a n

un populated area. Design values for all other sites in San Luis Obispo County are below the level of the standard, as are design values for sites in counties

located both to the north and to the south of San Luis Obispo County.

Previous studies have shown that ozone and ozone precursor emissions from

the San Joaquin Valley are transported west, impacting sites in eastern San Luis Obispo County, including Carrizo Plains and Red Hills

. O zone concentrations can also be impacted by transport south from the San Francisco Bay Area. In the absence of transport, it is likely that exceedances would not occur at these

sites. Therefore, r educing the transport impact will be critical to attaining the

federal standard

. Given that exceedances are limited to the eastern portion of the County, and all other sites meet the standard, ARB recommends that only the eastern portion of

San Luis Obispo County be designated as nonattainment.

Tuscan Buttes

Tusca n Buttes in Tehama County is located in the Sacramento Valley, where the majority of the land is near sea level. There are two monitors in the County. The

first site, Red Bluff

- Oak Street, is in the town of Red Bluff at an elevation of

322 feet

. While t he design value for this site currently meets the standard,

s everal of the high measurements at this site during 2008 may have been impacted by wildfires

. The District and ARB are currently reviewing this data, and if warranted, ARB plans to include docum entation to support the exclusion of

these measurement s as exceptional event s when we submit our designation

recommend ations to U.S. EPA in March 2009

.

The second monitor in Tehama County , Tuscan Buttes, has a design value of

0.085 ppm which exceeds the standard. Located at an elevation of 1,877 feet

, the Tuscan Buttes monitor is similar to the Sutter Buttes monitor in

Sutter County. Both of these monitors were sited to study high

- elevation transport of pollutants from the Sacramento urban nonattainmen t region into the upper Sacramento Valley , and t here are no pollution sources or populated areas

near either site. Furthermore, design values for low elevation sites in areas

## - 10

-

surrounding Tehama County (Colusa and Glenn counties and northern Sutter

Count y ) are below the level of the standard

, lending additional support to the
argument that the ozone problem at Tuscan Buttes is unique and isolated

.

Because of the elevated location and lack of population exposure at the Tuscan
Buttes site, ARB recommends the geographic scope of the nonattainment area

be limited to th at portion of the Tuscan Buttes area with an elevation of 1800 feet

or more

. This approach is c onsistent with the approach U.S. EPA used in designating the Sutter Buttes ozone nonattainment a rea.

Expanded Nonattainment Area

Eastern Kern

County

Kern County is located in two different air basins: the San Joaquin Valley

Air Basin and the Mojave Desert Air Basin. The eastern portion, located in the Mojave Desert Air Basin, falls under the jurisdiction of the Kern County

Air Pollution Control District. Currently, the Eastern Kern nonattainment area

, which does not

in clude Indian Wells Valley

, is designated as nonattainment based on a design value of 0.086 ppm for the Mojave

- Poole Street sit e.

In contrast , Indian Wells Valley (defined as the Kern County portion of h ydrologic

u nit 18090205 )

, in the northeastern p ortion of Kern County

, is designated as

attainment for the 0.08 ppm ozone standard

. Indian Wells Valley is a desert region that i ncludes the China Lake Naval Air Weapons Station and the town of Ridgecrest. Similar to the rest of Eastern Kern, Indian Wells Valley is sparsely populated, with few significant emissions sources. Furthermore, p revious studies

have shown that ozone conce ntrations in both of these areas are overwhelmingly impacted by transport from the San Joaquin Valley and South Coast air basins.

O zone data collected during 2006 through 2008 are available for a site located i n
the China Lake area of Indian Wells Valle y

. Although these data have not been

reviewed or forwarded to U.S. EPA, t he design value for the site , 0.0 81 ppm

, exceeds the federal standard and is comparable to the design value of

0.086 ppm for the Mojave

- Poole Street site in the existing Eastern Kern

nonattainment area. Because the design values for these two areas are similar in magnitude and both areas are impacted by ozone transported from the same upwind areas, ARB staff recommends that the existing Eastern Kern

nonattainment area be expanded to include Indian Wells Valley . As a result, the Eastern Kern ozone nonattainment area would include the entire Mojave Desert Air Basin portion of Kern County.

## - 11

-

Existing Nonattainment Areas

South Coast Air Basin

The South Coast Air Basin nonattainment area would continue to include all of

the South Coast Air Basin: w estern Los Angeles (including Catalina and

San Clemente Islands, which are not part of the Channel Islands), Orange,

s outhwestern San Bernardino, and w estern Riverside c ounties. This

nona ttainment area violates the 8

- hour standard with a design value of

0.119 ppm at the Crestline monitoring site in San Bernardino County.

San Joaquin Valley

The San Joaquin Valley nonattainment area would continue to comprise the

entire San Joaquin Valle y Air Basin: San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare

, and w estern Kern c ounties. The San Joaquin Valley

violates the federal 8

- hour standard with a design value of 0.10 8 ppm at the

Arvin

- Bear Mountain Blvd

. monitoring site in Kern County.

Sacramento Metro

Area

The Sacramento Metro nonattainment area w ould continue to include all of Sacramento and Yolo counties, southern Sutter County, the Sacramento Valley Air Basin portion of Solano County, the Sacramento Valley and Mountain

Co unties air basin portions of Placer County, and the Mountain Counties Air Basin portion of El Dorado County . This area violates the standard with a design

value of 0.102 ppm at the Folsom

- Natoma Street site in Sacramento County.
Although the nonattainmen t area involves multiple local air pollution control agencies, all but the Solano County portion are covered by a single
transportation planning agency.

San Francisco Bay Area

The San Francisco Bay Area nonattainment area w ould continue to comprise all of the San Francisco Bay Area Air Basin: Marin, Napa, Contra Costa, Alameda,
Santa Clara, San F rancisco, and San Mateo counties and the San Francisco Bay Area Air Basin portions of Solano and Sonoma counties . The area’s
nonattainment designation is base d on a design value of 0.081 ppm for the

Livermore

- 793 Rincon Avenue site in Alameda County.

Ventura County

The Ventura County 8

- hour nonattainment area would continue to include only

the continental portion of Ventura County

. Anacapa and San Nicolas I slands

, two of the Channel Islands , would not be included. Ventura Coun t y violates the

## - 12

-

federal standard with a design value of 0.088 ppm at the Simi Valley

- Cochran

Street site.

Western Mojave Desert

The Western Mojave Desert nonattainment area would continue to comprise the

central portion of San Bernardino County that is located in the Mojave Desert

Air Basin

. Ozone concentrations at a number of sites in this area violate the

federal 8

- hour standard , and the area has a design value of 0.104 ppm at t he

Joshua Tree

- N ational Monument site.

Antelope Valley

The Antelope Valley

nonattainment area would continue to comprise the portion

of Los Angeles County that is located in the Mojave Desert Air Basin

. The area

has a design value of 0.094 ppm at the L ancaster

- 43301 Division Stree t site.

Coachella Valley

The Coachella Valley ozone nonattainment area would continue to include the portion of Riverside County that is located in the Salton Sea Air Basin . The design value for this area is 0.097 ppm at the Palm Springs

- Fire Station site.

San Diego County

The 8

- hour nonattainment area would continue to include all of San Diego County. Ozone concentrations in the County exceed the standard at several

sites, and the design value is 0.092 ppm at Alpine

- Vic toria Drive

.

Imperial County

Similar to San Diego County, the Imperial County nonattainment area would

continue to include the entire C ounty. The design value for Imperial County is

0.082 ppm at both El Centro

- 9 th 

## Street and Westmorland

- West 1 st 

## Stree t

.

Sutter Buttes

The Sutter Buttes nonattainment area would continue to include that portion of the Sutter Buttes above 2000 feet elevation. Located in Sutter County, the design value for this area is 0.085 ppm at the Sutter Buttes site.

Central Mount

ain Counties

The Central Mountain Counties nonattainment area would continue to include all of Amador and Calaveras counties. The design value for this two

- county area is

0.089 ppm at the San Andreas

- Gold Strike Road site in Calaveras County.

## - 13

-

Southern Mo untain Counties

The Southern Mountain Counties nonattainment area would continue to include all of Mariposa and Tuolumne counties. The design value for this area is

0.088 ppm at the Turtleback Dome site in Yosemite National Park , which is in Mariposa Co unty

.

Western Nevada County

This nonattainment area would continue to comprise the western portion of Nevada County, up to the crest of the Sierra Nevada. The current design value for western Nevada County is 0.091 ppm at the Grass Valley

- Litton Buildin

g site

.

Butte County

This nonattainment area would continue to comprise all of Butte County. There are two monitoring sites in Butte County, and both have design values that

violate the standard. The Paradise

- 4405 Airport Road site has the higher val ue, with a design value of 0.085 ppm.

Attainment Areas

A number of areas in California have ozone monitoring data that are in

attainment of the 2008 federal 8

- hour standard according to the criteria established by U.S. EPA (U.S. EPA, December 1998, Gui deline on Data Handling Conventions for the 8

- Hour Ozone NAAQS ) . One of these areas, Shasta County

, attained the 0.08 ppm standard but has ozone data showing

violations of the federal 0.075 ppm standard. However, a number of days in this

area during 2008 were impacted by wildfires , an exceptional event

. If these days are excluded, Shasta County’s design value is below the 2008 federal 8

- hour

ozone standard. A second area, Eastern Riverside County, was previously designated as unclassified because of inc omplete data . Now that complete data
are available, the area qualifies as attainment. The remaining ten areas all have
design values in attainment of the 0.075 ppm ozone standard

, and ARB recommends they also be designated as attainment. All of the reco mmended

attainment areas are summariz ed in Table 2, below.

Shasta County

Currently, Shasta County in northern California is designated as attainment for

the federal 0.08 ppm ozone standard. There are three monitoring sites in Shasta County: Anderson

- North Street , Redding

- Health Department Roof , and Lassen

Volcanic National Park

- Manzanita Lake

. Using all data collected at these sites
during 2006 through 2008, the design values for both Anderson (0.076 ppm) and Lassen (0.077 ppm) are just slightly abov e the federal standard.

## - 14

-

During the summer of 2008, a significant number of wildfires in California impacted ambient ozone readings at sites throughout the State. Shasta County Air Quality Management District has documented these impacts and requested

that high ozone measurements during 1 6 days in June and July 2008 be

excluded as impacted by exceptional event s ( refer to Attachment A)

. ARB is still in the process of reviewing these da ta . However, i f the measurement s are

excluded in accordance with U.S

. EPA’s exceptional events rule, the revised design value would be 0.073 ppm for all three sites in Shasta County

.

If the impacted da ta are excluded, the design value for Shasta County i s below

the 2008 federal 8

- hour ozone standard

. Therefore, pending ARB concurrence

with the District’s evaluation, we recommend that Shasta County be designated

as attainment for the federal 8

- hour ozone standard

.

Eastern Riverside County

Riverside County is subdivided among three air basins: South Coast Air Basin,

Sa lton Sea Air Basin (Coachella Valley), and Mojave Desert Air Basin . The urbanized South Coast and Coachella Valley portions of the County have design

values that violate the standard

, and these areas are designated as nonattainment. In contrast, the east ern portion of Riverside County, located in

the Mojave Desert Air Basin, is sparsely populated, with few emissions sources. This portion of the County is currently designated as unclassified for the federal

8

- hour ozone standard.

When U.S. EPA designated areas for the 0.08 ppm ozone standard, complete

ozone monitoring data were not available for eastern Riverside County , and the area was designated as unclassified. Sinc e then, the ozone monitoring site at Blythe (Blythe

- 445 West Murphy Street) has contin ued to operate

. The Blythe data show a design value of 0.063 ppm, based on data collected during 2006 through 2008. Because this value is below the standard

, ARB recommends th at

eas tern Riverside County be designated as attainment for the 2008 federal

8

- hour ozone standard.

Other Areas

A number of other areas in California that were attainment or unclassified for the

0.08 ppm standard also qualify as attainment for the revised federal ozone

standard of 0.075 ppm. These areas are listed in Table 2

, a lo ng with their design

values

, based on data collected during 2006 through 2008 . ARB recommends

that all these areas be designated as attainment for ozone.

## - 15

- TABLE 2

Recommended California Attainment Areas

for the Federal 8

- Hour Ozone Standard

B ased on 20 06

- 2008 Ozone Air Quality Data

A ttainment Area Design

Value 1



## (ppm) Area Included

North Coast Air Basin 0.058 Del Norte, Humboldt, Mendocino, and Trinity

counties and the North Coast Air Basin portion of Sonoma County Shasta County 0.0 73 Shasta County

Tehama County 0.075 Portion of Tehama County outside Tuscan

Buttes area Glenn County 0.065 Glenn Count y 2



## Colusa County 0.069 Colusa County

Sutter and Yuba Counties 0.072 Yuba County and portion of Sutter County

outside Sacramento Metro A rea and Sutter

Buttes area Lake County 0.062 Lake County

Lake Tahoe Air Basin 0.070 Lake Tahoe Air Basin portions of El Dorado

and Placer counties

North Central Coast Air

Basin 0.069 Monterey County, Santa Cruz County,

San Benito County outside Pinnacles

National Mon ument boundary

Santa Barbara County 0.073 Continental portion of Santa Barbara County (excludes San Miguel, Santa Barbara, Santa Cruz, and Santa Rosa islands) Western San Luis Obispo County 0.06 8 Portion of County west of Eastern San Luis Obispo area

Ea stern Riverside County 0.063 Portion of Riverside County in Mojave Desert

Air Basin

1 

### The design value is the 3

- year average (2006

- 2008 data) of the annual fourth highest 8

- hour ozone concentration at the highest monitor (if greater than 0.075 ppm = nonat tainment; if less
than or equal to 0.075 = attainment). 2008 data are preliminary.

2 

### Reflects combined data from 2 monitoring sites.

## - 16

-

Unclassifiable Areas

The areas listed in Table 3 have either no ozone monitoring data or the available monitoring da ta do not meet completeness criteria established by U.S. EPA

. Therefore, ARB recommends they be considered unclassifiable at the current

time.

TABLE 3

Recommended California Unclassifiable Areas

for the Federal 8

- Hour Ozone Standard

Unclassifiable Ar

ea Area Included

Great Basin Valleys Air Basin Alpine County, Mono County, portion of Inyo County outside Southern Inyo County

nonattainment area

Northern Mountain Counties Plumas and Sierra counties

Northern Channel Islands T he islands located in the South Central Coast Air Basin, including Anacapa, San Miguel,

San Nicolas, Santa Barbara, Santa Cruz, and

Santa Rosa

Eastern Nevada County Portion of Nevada County east of the crest of the

Sierra Nevada mountains

Northeast Plateau Air Basin Lassen, Mod oc, and Siskiyou counties

## A TTACHMENT A

SUMMARY OF OZONE DATA

POTENTIALLY IMPACTED BY EXCEPTIONAL EVENTS

## A

- 1

INTRODUCTION

Under U.S. EPA’s guidance, air quality data may be excluded from the designation process if they were affected by an exceptional event. During 2007

and 2008, wildfires impacted air quality throughout California. However, there is only one area in the State, Shasta County, where excluding such data makes a difference between attainment and nonattainment based on the design value for
the 2006 through 2008 timeframe. The dates and sites being considered for identification as exceptional events for this area are listed in Table A

- 1, below.

In addition to Shasta County, there are other areas in California where it is uncertain if measurements impacted by wildfires would adversely affect their design values based on the 2007 through 2009 data that U.S. EPA is expected to use in determining the final area designations. It is also uncertain whether excluding such measurements would affect their classificati on with respect to the

0.075 ppm ozone standard. Therefore, additional dates and sites may be identified. ARB anticipates that documentation of all exceptional events will be

submitted to U.S. EPA in March 2009.

TABLE A

- 1

Summary of Dat

a Being Eva luated as Potentially Affected by Exceptional Events

COUNTY MONITORING SITE DATES

Anderson

- North St Jun 14

- 15, 24

- 25, 28

- 30, 2008
and Jul 2, 13, 17

- 19, 23

- 26, 2008

Lassen Vol NP_Manzanita Lk same dates as Anderson Shasta

Redding

- Health Dept Roof same dates as Anderson

## A TTACHMENT B

2006

- 2008 FEDERAL 8

- HOUR OZONE DESIGN VALUES BY SITE

## B

- 1 TABLE B

- 1

SUMMARY OF DATA AND FEDERAL 8

- HOUR OZONE DESIGN VALUES

FOR CALIFORNIA SITES BASED ON 2006 THROUGH 2008 DATA

Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.082 0.085 0.077 0.081 Inyo Death Valley Natl Monument Valid Days 347 351 320

Alpine NO MONITORS Great Basin Valleys

Mono NO MONITORS

4 th High 0.062 0.057 0.068 0.062 Lake County Lake Lakeport

- Lakepor t Blvd Valid Days 360 354 328

4 th High 0.069 0.070 0.072 0.070 El Dorado South Lake Tahoe

- Airport

Road Valid Days 160 169 151 Lake Tahoe

Placer NO MONITORS

4 th High 0.089 0.078 0.093 0.086 Kern Mojave

- 923 Poole S treet Valid Days 357 358 188

4 th High 0.098 0.091 0.095 0.094 Los Angeles Lancaster

- 43301 Division

Street Valid Days 363 357 360

4 th High 0.057 0.066 0.067 0.06 3 Riverside Blythe

- 445 West Murphy Street Valid Days 361 284 237

4 th High 0.086 0.084 0.090 0.086 Barstow Valid Days 344 356 364

4 th High 0.095 0.098 0.098 0.097 Hesperia

- Olive Street Valid Days 358 356 362

4 th High 0.103 0.104 0.105 0.104 Joshua Tree

- National

Monument Valid Days 348 342 322

4 th High 0.097 0.093 0.099 0.096 Phelan

- Beekley Rd & Phelan

Rd' Valid Days 363 356 365

4 th High 0.080 0.077 0.084 0.080 Trona

- Athol and Telegraph Valid Days 360 351 339

4 th High 0.091 0.087 0.089 0.089 Mojave Desert

San Bernardino

Victorville

- 143 06 Park Avenue Valid Days 363 362 359

4 th High 0.085 0.073 0.101 0.086 Amador Jackson

- Clinton Road Valid Days 363 344 265

4 th High 0.098 0.076 0.094 0.089 Calaveras San Andreas

- Gold Strike Road Valid Days 364 356 267

4 th High 0.099 0.093 0.102 0.098 Cool

- Highway 193 Valid Days 183 181 150

4 th High 0.075 0.075 0.078 0.076 Echo Summit Valid Days 148 135 135

4 th High 0.0 97 0.085 0.106 0.096 El Dorado

Placerville

- Gold Nugget Way Valid Days 363 333 272

4 th High 0.080 0.083 0.089 0.084 Mountain

Counties

Mariposa Jerseydale

- 6440 Jerseydale Valid Days 175 181 183

## B

- 2 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.084 0.087 0.094 0.088 Mariposa (continued) Yosemite NP

- Turtleback Dome Valid Days 292 334 317

4 th High 0.096 0.088 0.091 0.091 Grass Valley

- Litton Building Valid Days 328 365 247

4 th High 0.076 0.071 0.066 0.071 Truckee

- Fire Station Valid Days 225 281 265

4 th High 0.089 0.082 0.091 0.087 Nevada

White Cloud Mountain Valid Days 162 182 153

4 th High 0.105 0.079 0.084 0.089 Placer Colfax

- City Hall Valid Days 346 356 338

4 th High 0.064 0.064 Plumas Quincy

- N Churc h Street Valid Days 229

4 th High 0.079 0.084 0.098 0.087 Tuolumne Sonora

- Barretta Street Valid Days 365 360 271 Mountain

Counties (continued)

Sierra NO MONITORS

4 th High 0.060 0.059 0.060 0.0 59 Carmel Valley

- Ford Road Valid Days 364 365 332

4 th High 0.054 0.06 0.057 King City

- 415 Pearl Street Valid Days 215 304

4 th High 0.063 0.054 0.058 King City

- 750 Metz Road Valid Days 360 134

4 th High 0.054 0.053 0.060 0.055 Monterey

Salinas

- #3 Valid Days 3 58 354 322

4 th High 0.071 0.068 0.068 0.069 Hollister

- Fairview Road Valid Days 359 352 329

4 th High 0.078 0.075 0.086 0.079 San Benito

Pinnacles National Monument Valid Days 355 361 324

4 th High 0.052 0.049 0.056 0.05 2 Davenport Valid Days 364 362 322

4 th High 0.054 0.053 0.057 0.054 Santa Cruz

- 2544 Soquel Ave Valid Days 358 358 329

4 th High 0.062 0.059 0.064 0.061 Scotts Valley

- Scotts Valley Dr Valid Days 361 361 332

4 th Hig h 0.054 0.054 0.058 0.055 North Central

Coast

Santa Cruz

Watsonville

- Airport Boulevard Valid Days 363 364 334

4 th High 0.046 0.049 0.047 Humboldt Eureka

- Jacobs Valid Days 17 308 347

4 th High 0.060 0.053 0.061 0.058 Ukiah

- E Gobbi Street Valid Days 356 352 302

4 th High 0.049 0.046 0.045 0.046 North Coast

Mendocino

Willits

- 899 S Main Street Valid Days 351 358 149

## B

- 3 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.056 0.060 0.055 0 .057 Sonoma Healdsburg

- Municipal Airport Valid Days 338 341 271

Del Norte NO MONITORS North Coast (continued)

Trinity NO MONITORS

4 th High 0.067 0.060 0.058 0.061 Siskiyou Yreka

- Foothill Drive Valid Days 318 332 264

Lassen NO MONITORS Northeast Plateau

Modoc NO MONITORS

4 th High 0.076 0.074 0.080 0.076 C hico

- Manzanita Avenue Valid Days 360 363 262

4 th High 0.089 0.083 0.084 0.085 Butte

Paradise

- 4405 Airport Road Valid Days 361 364 269

4 th High 0.069 0.066 0.072 0.069 Colusa Colusa

- Sunrise Blvd Valid Days 357 361 269

4 th High 0.059 0.069 0.067 0.065 Willows

- 720 N Colusa Street Valid Days 106 361 271

4 th High 0.063 0.063 Glenn

Willows

- E Laurel Street Valid Days 252

4 th High 0.098 0.079 0.095 0.090 Auburn

- Dewitt

- C Avenue Va lid Days 330 347 351

4 th High 0.094 0.082 0.094 0.090 Placer

Roseville

- N Sunrise Blvd Valid Days 363 350 271

4 th High 0.087 0.078 0.082 0.082 Elk Grove

- Bruceville Road Valid Days 357 359 330

4 th High 0.102 0.090 0.114 0.102 Folsom

- Natoma Street Valid Days 358 354 327

4 th High 0.092 0.071 0.072 0.078 North Highlands

- Blackfoot Way Valid Days 356 341 245

4 th High 0.077 0.077 0.080 0.078 Sacramento

- 3801 Airport Road Valid Days 311 299 201

4 th High 0.093 0.081 0.087 0.087 Sacramento

- Del Paso Manor Valid Days 349 362 323

4 th High 0.084 0.073 0.081 0.079 Sacramento

- T Street Valid Days 351 342 292

4 th High 0.104 0.080 0.102 0.095 Sacramento

Sloughhouse Valid Days 214 208 212

4 th High 0.073 0.075 0.081 0.076 Anderson

- North Street Valid Days 327 365 274

4 th High 0.074 0.076 0.083 0.077 Lassen Vol NP

- Manzanita Lk Valid Days 353 362 316

4 th High 0.080 0.070 0.077 0.075 Sacramento
Valley

Shasta

Redding

- Health Dept Roof Valid Days 357 365 338

## B

- 4 Year

Bas in Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.080 0.071 0.084 0.078 Solano Vacaville

- Ulatis Drive Valid Days 358 365 354

4 th High 0.090 0.077 0.088 0 .085 Sutter Buttes

- S Butte Valid Days 184 183 153

4 th High 0.078 0.072 0.068 0.072 Sutter

Yuba City

- Almond Street Valid Days 352 343 264

4 th High 0.073 0.072 0.080 0.075 Red Bluff

- Oak Street Valid Days 330 357 319

4 th High 0.087 0.082 0.087 0 .085 Tehama

Tuscan Butte Valid Days 183 184 146

4 th High 0.078 0.075 0.077 0.076 Davis

- UCD Campus Valid Days 358 359 258

4 th High 0.088 0.073 0.076 0.079 Yolo

Woodland

- Gibson Road Valid Days 365 363 356 Sacramento Valley (continued)

Yuba NO MONITORS

4 th High 0.043 0.067 0.057 0.055 Brawley

- 220 M ain Street Valid Days 91 89 14

4 th High 0.078 0.083 0.078 0.079 Calexico

- East Valid Days 352 325 341

4 th High 0.068 0.087 0.087 0.080 Calexico

- Ethel Street Valid Days 362 353 363

4 th High 0.065 0.071 0.068 Calexico

- Grant Stree t Valid Days 356 205

4 th High 0.091 0.083 0.074 0.082 El Centro

- 9th Street Valid Days 331 349 362

4 th High 0.072 0.078 0.075 0.075 Niland

- English Road Valid Days 354 355 362

4 th High 0.086 0.085 0.077 0.082 Imperial

Westmorland

- W 1st Street Valid Days 355 353 360

4 th High 0.085 0.087 0.088 0.086 Indio

- Jackson Street Valid Days 361 360 237

4 th High 0.079 0.076 0.084 0.079 Joshua Tree National Park Valid Days 270 281 129

4 th High 0.099 0.097 0.096 0.097 Salton Sea

Riverside

Palm Springs

- Fire Station Valid Days 354 360 241

4 th High 0.094 0.086 0.098 0.092 Alpine

- Victoria Drive Valid Days 357 358 301

4 th High 0.072 0.071 0.070 0.071 Camp Pendleton Valid Days 355 349 300

4 th High 0.065 0.070 0.074 0.069 Chula Vista Valid Days 357 351 299

4 th High 0.067 0.072 0.075 0.071 San Diego San Diego

Del Mar

- Mira Costa College Valid Days 364 362 305

## B

- 5 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.076 0.073 0.082 0.077 El Cajon

- Redwood Avenue Valid Days 349 332 297

4 th High 0.078 0.075 0.089 0.080 Escondido

- E Valley Parkway Valid Days 352 355 291

4 th High 0.061 0.064 0.066 0.063 Otay Mesa

- Paseo Internati onal Valid Days 359 357 273

4 th High 0.061 0.060 0.063 0.061 San Diego

- 1110 Beardsley St Valid Days 362 330 291

4 th High 0.07 0.073 0.082 0.075 San Diego (continued) San Diego

(continued)

San Diego

- Overland Avenue Valid Days 354 357 296

4 th High 0.029 0.045 0.037 Berkeley

- 6th Street Valid Days 23 269

4 th High 0.069 0.055 0.061 0.061 Fremont

- Chapel Way Valid Days 358 352 271

4 th High 0.067 0.055 0.068 0.063 Hayward

- La Mesa Valid Days 244 242 182

4 th High 0.089 0.067 0.087 0.081 Livermore

- 793 Rincon Avenue Valid Days 361 361 270

4 th High 0.034 0.057 0.045 Oakland

- Davie Valid Days 60 268

4 th High 0.06 0.052 0.067 0 .059 Alameda

San Leandro

- County Hospital Valid Days 243 243 175

4 th High 0.081 0.071 0.076 0.076 Bethel Island Road Valid Days 358 360 271

4 th High 0.085 0.071 0.078 0.078 Concord

- 2975 Treat Blvd Valid Days 360 360 270

4 th High 0. 079 0.067 0.067 0.071 Pittsburg

- 10th Street Valid Days 357 356 271

4 th High 0.045 0.049 0.057 0.050 Contra Costa

San Pablo

- Rumrill Blvd Valid Days 353 356 265

4 th High 0.047 0.048 0.055 0.050 Marin San Rafael Valid Days 353 356 266

4 t h High 0.064 0.055 0.067 0.062 Napa Napa

- Jefferson Avenue Valid Days 361 355 269

4 th High 0.044 0.047 0.049 0.046 San Francisco San Francisco

- Arkansas Street Valid Days 347 354 266

4 th High 0.051 0.052 0.058 0.053 San Mateo Redwood City Valid Days 354 357 266

4 th High 0.08 0.068 0.072 0.073 Gilroy

- 9th Street Valid Days 229 240 183

4 th High 0.085 0.059 0.074 0.072 Los Gatos Valid Days 363 363 273

4 th High 0.073 0.057 0.067 0.065 San Fran cisco
Bay Area

Santa Clara

San Jose

- Jackson Street Valid Days 329 352 269

## B

- 6 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.088 0.070 0.071 0.076 San Martin

- Murphy Avenue Valid Days 238 239 182

4 th High 0.064 0.054 0.063 0.060 Santa Clara (continued) Sunnyvale

- 910 Ticonderoga Valid Days 243 243 183

4 th High 0.063 0.075 0.069 Benicia

- East 2nd Street Valid Days 270 266

4 th High 0.074 0.062 0.068 0.0 68 Fairfield

- Chadbourne Road Valid Days 242 241 183

4 th High 0.06 0.054 0.067 0.060 Solano

Vallejo

- 304 Tuolumne Street Valid Days 346 354 267

4 th High 0.049 0.047 0.059 0.051 San Francisco Bay Area (continued)

Sonoma Santa Rosa

- 5th Street Valid Days 362 357 269

4 th High 0.094 0.092 0.108 0.098 Clovis

- N Villa Avenue Valid Days 357 341 269

4 th High 0.101 0.094 0.108 0.101 Fresno

- 1st Street Valid Days 362 360 265

4 th High 0.085 0.079 0.093 0.085 Fresno

- Drummond Street Valid Days 359 357 241

4 th High 0.097 0.088 0.101 0.095 Fresno

- Sierra Skypark #2 Valid Days 355 359 262

4 th High 0.099 0.090 0.094 0.094 Fresno

Parlier Valid Days 339 356 231

4 th High 0.111 0.102 0.112 0.108 Arvin

- Bear Mountain Blvd Valid D ays 350 353 292

4 th High 0.107 0.085 0.101 0.097 Bakersfield

- 5558 California Ave Valid Days 348 361 298

4 th High 0.091 0.08 0.094 0.088 Bakersfield

- Golden State Hwy Valid Days 362 358 209

4 th High 0.108 0.093 0.107 0.102 Edison Vali d Days 361 361 301

4 th High 0.09 0.086 0.084 0.086 Maricopa

- Stanislaus Street Valid Days 351 291 265

4 th High 0.100 0.090 0.104 0.098 Oildale

- 3311 Manor Street Valid Days 354 357 303

4 th High 0.093 0.083 0.0 93 0.089 Kern

Shafter

- Walker Street Valid Days 361 353 303

4 th High 0.086 0.080 0.083 Kings Hanford

- S Irwin Street Valid Days 339 297

4 th High 0.081 0.077 0.091 0.083 Madera Madera

- Pump Yard Valid Days 363 360 250

4 th High 0.086 0.087 0.105 0.092 Merced Merced

- S Coffee Avenue Valid Days 167 363 256

4 th High 0.083 0.075 0.077 0.078 San Joaquin Valley

San Joaquin Stockton

- Hazelton Street Valid Days 362 361 267

## B

- 7 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Valu e

4 th High 0.093 0.079 0.090 0.087 San Joaquin (continued) Tracy

- Airport Valid Days 355 354 269

4 th High 0.090 0.076 0.090 0.085 Modesto

- 14th Street Valid Days 358 362 268

4 th High 0.092 0.075 0.106 0.091 Stanislaus

Turlock

- S Minaret Str eet Valid Days 363 361 265

4 th High 0.104 0.099 0.112 0.105 Sequoia & Kings Canyon NP Valid Days 300 238 232

4 th High 0.097 0.091 0.101 0.096 Sequoia NP

- Lower Kaweah Valid Days 348 360 325

4 th High 0.092 0.086 0.105 0.094 San Joaquin Valley (continued)

Tulare

Vis alia

- N Church Street Valid Days 361 361 301

4 th High 0.071 0.066 0.069 0.068 Atascadero

- Lewis Avenue Valid Days 356 352 330

4 th High 0.086 0. 080 0.088 0.084 Carrizo Plains School

- Carrizo Valid Days 340 349 322

4 th High 0.053 0.053 0.058 0.054 Morro Bay Valid Days 351 343 320

4 th High 0.055 0.056 0.066 0.059 Nipomo

- Regional Park Valid Days 345 351 325

4 th High 0.072 0.068 0 .064 0.068 Paso Robles

- Santa Fe Avenue Valid Days 360 363 190

4 th High 0.084 0.092 0.088 Red Hills Valid Days 362 330

4 th High 0.055 0.057 0.060 0.057 San Luis Obispo

San Luis Obispo

- S Higuera St Valid Days 356 356 242

4 th High 0.058 0.066 0.072 0.065 Carpinteria

- Gobernador Road Valid Days 349 354 272

4 th High 0.056 0.057 0.066 0.059 El Capitan Beach Valid Days 364 364 299

4 th High 0.055 0.055 0.058 0.056 Gaviota

- GTC Site B Valid Days 360 362 241

4 th High 0.064 0.057 0.062 0.061 Goleta

- Fairview Valid Days 364 358 301

4 th High 0.07 0.078 0.070 0.072 Las Flores Canyon #1 Valid Days 363 360 330

4 th High 0.062 0.066 0.067 0.065 Lompoc

- HSandP Valid Days 363 358 301

4 th High 0.051 0.056 0.062 0.056 Lompoc

- S H Street V alid Days 362 356 302

4 th High 0.075 0.077 0.068 0.073 Paradise Road

- Los Padres NF Valid Days 363 355 301

4 th High 0.056 0.063 0.062 0.060 South Central

Coast

Santa Barbara

Santa Barbara

- E Canon

Perdido Valid Days 357 359 240

## B

- 8 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.048 0.048 0.056 0.050 Santa Maria

- 906 S Broadway Valid Days 349 354 217

4 th High 0.064 0.063 0.067 0.064 Santa Ynez

-

Airport Road Valid Days 364 363 301

4 th High 0.059 0.069 0.065 0.064 Santa Barbara (continued)

Vandenberg AFB

- STS Power Valid Days 356 358 331

4 th High 0.059 0.061 0.065 0.061 El Rio

- Rio Mesa School #2 Valid Days 364 351 297

4 th High 0.094 0.076 0.081 0.083 Ojai

- Ojai Avenue Valid Days 363 361 301

4 th High 0.085 0.076 0.081 0.080 Piru

- 3301 Pacific Avenue Valid Days 359 358 304

4 th High 0.089 0.086 0.090 0.088 Simi Valley

- Cochran Street Valid Days 360 357 295

4 th High 0 .076 0.074 0.077 0.075 Thousand Oaks

- Moorpark

Road Valid Days 364 358 301

4 th High 0.062 0.065 0.067 0.064 Ventura

Ventura

- Emma Wood State

Bch Valid Days 362 350 294 South Central Coast (continued)

Channel Islands NO MONITORS

4 th High 0.091 0.096 0.101 0.096 Azusa Valid Days 357 355 236

4 th High 0.098 0.088 0.092 0.092 Burbank

- W Palm Avenue Valid Days 358 356 235

4 th High 0.106 0.105 0.112 0.107 Glendora

- Laurel Valid Days 354 352 241

4 th High 0.095 0.063 0.079 Lebec

- Peace Valley Road Valid Days 321 82

4 th High 0.075 0.072 0.073 0.073 Los Angeles

- North Main Street Valid Days 355 337 224

4 th High 0.062 0.067 0.065 0.064 Los Angeles

- Westchester

Pkwy Valid Days 358 355 221

4 th High 0.064 0.057 0.055 0.058 Lynwood Valid Days 357 357 235

4 th High 0.057 0.057 0.064 0.059 North Long Beach Valid Days 354 350 236

4 th High 0.096 0.090 0.091 0.092 Pasadena

- S Wilson Avenue Valid Days 360 357 232

4 th High 0.078 0.079 0.077 0.078 Pico Rivera

- 4144 San Gabriel Valid Days 222 3 52 233

4 th High 0.108 0.103 0.100 0.103 Pomona Valid Days 354 352 238

4 th High 0.104 0.093 0.095 0.097 South Coast Los Angeles

Reseda Valid Days 355 339 242

## B

- 9 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.112 0.102 0.103 0.105 Santa Clarita Valid Days 357 351 235

4 th High 0.068 0.067 0.075 0.070 Los Angeles (continued) West Los Angeles

- VA Hospital Valid Days 360 345 236

4 th High 0.071 0.074 0.076 0.073 Anaheim

- Pampas Lane Valid Days 361 357 239

4 th High 0.061 0.065 0.073 0.066 Costa Mesa

- Mesa Verde Drive Valid Days 362 341 236

4 th High 0.09 0.082 0.078 0.083 La Habra Valid Days 349 355 238

4 th High 0.09 0.081 0.092 0.087 Orange

Mission Viejo

- 26081 Via Pera Valid Days 353 358 239

4 th High 0.105 0.095 0.108 0.102 Banning Airport Valid Days 353 359 237

4 th High 0.102 0.097 0.108 0.102 Lake Elsinore

- W Flint Street Valid Days 353 352 239

4 th High 0.114 0.103 0.1 06 0.107 Perris Valid Days 348 362 243

4 th High 0.112 0.099 0.111 0.107 Riverside

Riverside

- Rubidoux Valid Days 358 356 236

4 th High 0.111 0.126 0.120 0.119 Crestline Valid Days 363 365 234

4 th High 0.114 0.113 0. 110 0.112 Fontana

- Arrow Highway Valid Days 351 346 234

4 th High 0.125 0.112 0.112 0.116 Redlands

- Dearborn Valid Days 364 362 244

4 th High 0.119 0.117 0.112 0.116 San Bernardino

- 4th Street Valid Days 356 352 236

4 th High 0.112 0.112 0.108 0.110 South Coas t (continued)

San Bernardino

Upland Valid Days 360 354 236



### * 2008 data are preliminary and may not be complete. Therefore, the 2008 Design Value should be
considered preliminary.

## 1 ENCLOSURE 3

STATE OF CALIFORNIA

INFORMATION TO SUPPORT

NONATTAINMENT AREA BOUNDARY RECOMMENDATIONS

FOR THE 2008 FEDERAL 8

- HOUR OZONE STANDARD

CONTINUING NONATTAI N MENT AREAS

Because the 2008 revised 8

- hour ozone standard (0.075 parts per million (ppm)) is more stringent than the previous 8

- hour standard (0.08 ppm), all areas that
were nonattainment for the previous standard continue to be nonattainment under the revised standard. These continuing nonattainment areas and their
respective boundaries were justified when they were designated for the previous standard. ARB staff recommends retaining the current boundaries for 15 of the
16 areas, as summarized below. In addition , ARB staff recommends expanding the current Eastern Kern County nonattainment a rea, as described in the section

titled “New and

Expanded Nonattainment Areas,” below.

South Coast Air Basin

Based on 2006 through 2008 monitoring data, the South Coast Air Basin remains

nonattainment for the revised 8

- hour ozone standard with a design value of

0.119 ppm for the Crestline (Lake Gregory) site in San Bernardino County.

The recommended South Coast Air Basin ozone nonattainment area would

continue to include western Los Angeles County (including San Clemente and

Santa Catalina islands), O range County, western Riverside County, and

southwestern San Bernardino County. This area falls under the jurisdiction of the South Coast Air Quality Management District (AQMD).

San Joaquin Valley

The San Joaquin Valley nonattainment area would continu e to comprise the

entire San Joaquin Valley Air Basin: San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare, and western Kern counties. The San Joaquin Valley

violates the federal 8

- hour standard with a design value of 0.108 ppm at the

Arvin

- Be ar Mountain Blvd. monitoring site in Kern County. This area is under the jurisdiction of the San Joaquin Valley Air Pollution Control District (APCD).

Sacramento Metro Area

The Sacramento Metro nonattainment area would continue to include all of

Sacra mento and Yolo counties, southern Sutter County, the Sacramento Valley Air Basin portion of Solano County, the Sacramento Valley and Mountain Counties air basin portions of Placer County, and the Mountain Counties

## 2

Air Basin portion of El Dorado County. Th is area violates the standard with a design value of 0.102 ppm at the Folsom

- Natoma Street site in Sacramento County. Th e Sacramento Metro nonattainment area involves multiple local air pollution control agencies, including the Sacramento Metro, El Dorado County,

Feather River, and Yolo

- Solano AQMDs and the Placer County APCD.
However, all but the Solano County portion of the nonattainment area are covered by a single transportation planning agency.

San Francisco Bay Area

The San Francisco Bay Area no nattainment area would continue to comprise all of the San Francisco Bay Area Air Basin: Alameda, Contra Costa, Marin, Napa,

San Francisco, San Mateo , and Santa Clara counties and the San Francisco Bay Area Air Basin portions of Solano and Sonoma counties . The area’s nonattainment designation is based on a design value of 0.081 ppm for the

Livermore

- 793 Rincon Avenue site in Alameda County. The nonattainment area falls under the jurisdiction of the Bay Area AQMD.



# Ventura County

The Ventura County 8

- ho ur nonattainment area would continue to include only the continental portion of Ventura County. Anacapa and San Nicolas Islands, two of the Channel Islands, would not be included. Ventura County violates the federal standard with a design value of 0.088 ppm at the Simi Valley

- Cochran

Street site. This area is under the jurisdiction of the Ventura County APCD.

Western Mojave Desert

The Western Mojave Desert nonattainment area would continue to comprise the central portion of San Bernardino County that is located in the Mojave Desert

Air Basin. Ozone concentrations at a number of sites in this area violate the

federal 8

- hour standard, and the area has a design value of 0.104 ppm at the

Joshua Tree

- National Monument site. The Mojave Desert AQMD has juri sdiction

over this area.

Antelope Valley

The Antelope Valley nonattainment area , under the jurisdiction of the Antelope Valley AQMD, would continue to comprise the portion of Los Angeles County that is located in the Mojave Desert Air Basin. The area ha s a design value of

0.094 ppm at the Lancaster

- 43301 Division Street site.

## 3

Coachella Valley

The Coachella Valley ozone nonattainment area would continue to include the portion of Riverside County that is located in the Salton Sea Air Basin. The
design value for this area is 0.097 ppm at the Palm Springs

- Fire Station site. Coachella Valley is under the jurisdiction of the South Coast AQMD.

San Diego County

Th is 8

- hour nonattainment area falls under the jurisdiction of the San Diego County APCD and w ould continue to include all of San Diego County. Ozone concentrations in the County exceed the standard at several sites, and the
design value is 0.092 ppm at Alpine

- Victoria Drive.

Imperial County

Similar to San Diego County, the Imperial County non attainment area would continue to include the entire County. The design value for Imperial County is

0.082 ppm at both El Centro

- 9 th 

## Street and Westmorland

- West 1 st 

## Street. The County is under the jurisdiction of the Imperial County APCD.

Sutter Buttes

The Sutter Buttes nonattainment area would continue to include that portion of the Sutter Buttes above 2000 feet elevation. Located in Sutter County, the design value for this area is 0.08 5 ppm at the Sutter Buttes site, and the area is under the jurisdi ction of the Feather River AQMD.

Central Mountain Counties

The Central Mountain Counties nonattainment area would continue to include all

of Amador and Calaveras counties , under the jurisdiction of the Amador County and Calaveras County APCDs, respectiv ely . The design value for this

two

- county area is 0.089 ppm at the San Andreas

- Gold Strike Road site in Calaveras County.

Southern Mountain Counties

The Southern Mountain Counties nonattainment area would continue to include
all of Mariposa and Tuolumne counties. The design value for this area is

0.088 ppm at the Turtleback Dome site in Yosemite National Park, which is in Mariposa County. The two counties are under the jurisdiction of the Mariposa County APCD and the Tuolumne County APCD.

## 4

Western Nev ada County

This nonattainment area would continue to comprise the western portion of Nevada County, up to the crest of the Sierra Nevada. The Northern Sierra AQMD has jurisdiction over this area. The current design value for western Nevada County is 0.0 91 ppm at the Grass Valley

- Litton Building site.

Butte County

This nonattainment area would continue to comprise all of Butte County , which falls under the jurisdiction of the Butte County AQMD . There are two monitoring sites in Butte County, and both have design values that violate the standard. The

Paradise

- 4405 Airport Road site has the higher value, with a design value of

0.085 ppm.

NEW AND EXPANDED NONATTAINMENT AREAS

The following six areas represent new or expanded nonattainment areas under

the revised standard. Because the revised standard is set at a lower level, it brings in areas that increasingly rural in nature. In addition to being rural, ozone concentrations in all of the new and expanded areas are dominated by transport
from an up wind urban area. With the addition of t he new areas , California will

have a total of 21 ozone nonattainment areas.

Justification for each of the new and expanded areas is outlined below, using the

nine factors U.S. EPA included in its guidance memo ( De cember 4, 2008, Area Designations for the 2008 Revised Ozone National Ambient Air Quality
Standards, Memorandum from Robert J. Meyers, Principal Deputy Assistant Administrator, Office of Air and Radiation to Regional Administrators, Regions I

-

X ). These fa ctors include air quality data, emissions data, population density and degree of urbanization, traffic and commuting patterns, growth rates
and patterns, meteorology, geography and topography, jurisdictional boundaries,

and level of control of emission sou rces.

Northeast San Bernardino County

Jurisdictional Boundaries:

The southwest and central portions of San Bernardino County, which are under the jurisdiction of the South Coast AQMD and the Mojave Desert AQMD, respectively, were designated as nona ttainment for the previous 8

- hour ozone

standard. ARB staff recommends these areas continue as two distinct

nonattainment areas for the revised 2008 standard.

## 5

In contrast, the northeast portion of the County did not violate the previous
standard, but does violate the revised standard. Although this area also falls under the jurisdiction of the Mojave Desert AQMD, it is sufficiently different in terms of air quality, emissions, population, and other human, economic, and geographic factors that ARB staf f recommends it be designated as a separate nonattainment area. Designating Northeast San Bernardino County separately will give this area a classification consistent with its overall air quality problem

and will facilitate a more timely attainment findin g.

Geography / Topography:

San Bernardino County is the largest county in the United States (refer to
Figure 1). At just over 20,000 square miles, it encompasses a very diverse set of geographic conditions, from the over 11,000 foot mountain peaks in the southwest (South Coast Air Basin) portion of the County, to the high desert areas of the central (Western Mojave Desert) portion, to the low desert areas in the eastern (Northeast S an Bernardino County) portion. The variety of physical

conditions h as impacted the way the County has grown and resultant air quality.

FIGURE 1

SAN BERNARDINO COUNTY

## 6

Meteorology:

The variety of landscapes within San Bernardino County make s for a variety of different climate areas. Rainfall and temperatures sho w substantial variation throughout the area. The South Coast portion of the County receives an average

of 16 inches of rainfall each year, with a maximum monthly average temperature

of 97 degrees Fahrenheit. In contrast, the central portion receives an a verage of

6 inches of rainfall each year, with an average maximum summer temperature of

102 degrees Fahrenheit. In the northeast portion of the County, rainfall averages

4 inches per year, and the average maximum summer temperature is

107 degrees Fahrenhe it.

Information about meteorology, ozone concentrations, and transport within the

n ortheast portion of the County is based on data for Trona and for sites in the surrounding area at Ridgecrest, Mojave National Preserve, Jean (Nevada), Blythe, Barstow, a nd Mojave. Additional information is based on back trajectories constructed as part of an ozone transport assessment.

Northeast San Bernardino County is rural in nature, with extremely low population and few significant emissions sources. Because loca l emissions are low, locally measured ozone concentrations reflect the impact of long range transport from upwind urban areas. Based on general wind patterns, Northeast

San Bernardino County is downwind of several high emission source areas

, including the highly urbanized South Coast and San Joaquin Valley air basins.
Previous ARB transport assessments have found that the transport contribution

from both the South Coast and the San Joaquin Valley into the desert portions of

San Bernardino County can be ov erwhelming. An evaluation of back trajectories

corroborate s these findings.

Air Quality Data:

There is one ozone monitor in Northeast San Bernardino County, located at Trona (refer to Figure 1). The design value for this site is 0.080 ppm, base d on data for 2006 through 2008. This value does not violate the previous 8

- hour

standard, but it is does violate the revised standard. As shown in Table 1, the design value for Northeast San Bernardino County is significantly lower than the design value s for the Western Mojave Desert portion of the County and for the
upwind areas of the South C o ast and the San Joaquin Valley. The design value for the northeast portion of the County is less than 10 percent above the level of the standard, while design values for the other three areas are 40 to 60 percent above the standard. Because of the significant difference s in design value, the northeast portion of the County should be designated separately and given a classification that is commensurate with the overall magnitude of the ozone problem in this area.

## 7 TABLE 1

8

- HOUR OZONE DESIGN VALUES FOR VARIOUS PORTIONS OF

SAN BERNARDINO COUNTY AND UPWIND AREAS

BASED ON 2006 THROUGH 2008 DATA

AREA DESIGN SITE DESIGN

VALUE (ppm) PERCENT

ABOVE

STANDARD

NE San Bernardino Portion of County Trona 0.080 7%

Western Mojave Desert Portion of County Joshua Tree

- NM 0.104 39%

South Coast Air Basin Portion of County Crestline 0.119 59%

San Joaquin Valley Air Basin Arvin 0.108 44%

The design value trends for all four areas are shown in Figure 2. It is apparen t from the graph that design values for the South Coast and Western Mojave Desert Air Basin portions of the County, as well as for the San Joaquin Valley, are higher than that for Northeast San Bernardino County. However, regardless
of level, the design v

alue trend s for the Western Mojave Desert and Northeast portions of San Bernardino County mirror those for the South Coast and

San Joaquin Valley. This reflects the overwhelming impact of transport in these areas, where improvements in ozone air quality a re tied to improvements in the
upwind urban area.

FIGURE 2

Ozone Design Values for Subareas of

San Bernardino County and Upwind Areas

0.000 0.020 0.040 0.060 0.080 0.100 0.120 0.140 0.160

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Ozone DV (ppm)

Northeast San Bernardino County Western Mojave Desert Portion

South Coast Air Basin Portion San Joaquin Valley

## 8

P ast control strategies for both the South Coast and the San Joaquin Valley have relied heavily on reducing reactive organic gas (ROG) emissions. While this strategy has been effective in r educing ozone close to the urban areas, ozone in
transport

- impacted areas has not seen the same level of improvement. Future strategies will rely more heavily on reducing oxides of nitrogen (NOx) emissions. ARB expects ozone concentrations in the northea st and Western Mojave Desert portions of San Bernardino County will begin to decrease at a faster rate as emission control strategies contained in the recently submitted State Implementation Plan

begin to be effective.

Population Density and Degree of Urbanization; Growth Rates and Patterns; and Traffic and Commuting Patterns:

Similar to air quality, there are vast differences among the population in each of

the three San Bernardino County sub areas. Based on an analysis of census
data, Table 2 give s a summary of the size of each area and its population. More

than three

- quarters of the County population lives in the highly urbanized, South Coast portion of San Bernardino County. Most of the rest of the County population (20 percent) lives in the We stern Mojave Desert portion. Less than

2 percent live in Northeast San Bernardino County. Because Northeast

San Bernardino County is so large, the population density is very low , with less than 2 people per square mile. This compares with more than 1,100 p eople per square mile in the South Coast portion of the County, and 47 people per square mile in the Western Mojave Desert portion.

With higher population numbers and densities comes a greater degree of urbanization and generally higher growth rates, beca use of the jobs and

convenience associated with the urban area. San Bernardino County is no exception. The Western Mojave Desert portion of the County is closely linked to the South Coast portion because of its proximity to the larger urban area. Many

p eople within this area commute to jobs in the South Coast, while others work in the cities that have developed close to the South Coast / Western Mojave
boundary. These ties are less obvious, as one moves further away from the South Coast area, into the n ortheast portion of the County.

Over time, both the South Coast and Western Mojave Desert portions of

San Bernardino County have seen much higher growth rates when compared

with Northeast San Bernardino County. Table 2 shows these different rates from 1990 to 2000. Growth rates in the urbanized portions of the County have been
more than triple the rates in the northeast. This discrepancy in growth is expected to continue.

## 9 TABLE 2

8

- HOUR OZONE DESIGN VALUES FOR VARIOUS PORTIONS OF

SAN BERNARDIN O COUNTY BASED ON 2006 THROUGH 2008 DATA

AREA SIZE (square miles) POPULATION GROWTH IN

POPULATION (1990

- 2000) PEOPLE PER

SQUARE

MILE

NE San Bernardino County Portion 11,470 25,941 + 6% 2

Western Mojave Desert Portion 7,503 350,426 + 22 % 47

South Coas t Air Basin Portion 1,132 1,333,067 + 20 % 1,178

Emissions Data and Level of Emission Controls

Similar to population, there are vast differences in ozone precursor emissions among the three C ounty sub areas (refer to Table 3). In terms of number, ARB’s
emissions inventory shows five times more facilities in the Western Mojave Desert portion (125 facilities) and more than 10 times more in the South Coast
portion (320 facilities), as are located in Northeast San Bernardino County (26 facilities). Facilit ies tend to be concentrated in the urban areas and along the major roadways in the South Coast and Western Mojave Desert portions, in contrast to being scattered throughout the area in Northeast San Bernardino County.

TABLE 3

TOTAL ROG AND NOx EMISSIO NS IN VARIOUS PORTIONS

OF SAN BERNARDINO COUNTY

AREA TONS / DAY ROG TONS / DAY NOx NE San Bernardino County Portion 10.4 19.5 Western Mojave Desert Portion 48.4 149.5

South Coast Air Basin Portion 81.6 92.3

In combination, facilities in the South C oast and Western Mojave Desert portions of the County emit three and ten times more NOx and ROG than facilities in the northeast portion of the County. When mobile source emissions are added in, the discrepancy is similar (refer to Table 3). Total emissi ons of ROG and NOx in the South Coast and Western Mojave Desert portions of the County are five to eight times higher than in Northeast San Bernardino County. In terms of mobile source emissions, the dense network of streets and freeways in the South Coas t portion of San Bernardino County carry significant amounts of traffic, averaging over 38 million vehicle miles travelled (VMT) each day. In contrast, the more

## 10

limited networks in the Western Mojave Desert and Northeast portions of

San Bernardino County average less than half that amount (19.8 million VMT each day). The bulk of the daily VMT in these areas is concentrated near the South Coast portion of the County.

In terms of emissions controls, the statewide mobile source and consumer product regulations f orm the cornerstone of the attainment strategy for rural

transport

- impacted areas, along with the emission s reduction controls in the upwind regions of the South Coast and San Joaquin Valley. In addition, the Mojave Desert AQMD has adopted rules to reduce emissions from existing, as well as new or modified stationary sources under its jurisdiction.

Summary and Recommendation:

In summary, the air quality problem in Northeast San Bernardino County is much less severe than in the Western Mojave Desert por tion of the County. Ozone concentrations in the northeast County are overwhelmed by transport, even more
so than in the Western Mojave Desert portion. As a result, the primary attainment strategy will rely on statewide controls and control measures
imple mented by upwind districts. Although there are few stationary emissions

sources in Northeast San Bernardino County, there are few significant differences in the control requirements for stationary sources under the jurisdiction of the Mojave Desert AQMD.

Although Northeast San Bernardino County is contiguous with the Western Mojave Desert nonattainment area, and both areas will rely on controls in upwind areas to reach attainment, the magnitude of their problems is substantially

different. Therefore, AR B recommends Northeast San Bernardino County be designated as a separate nonattainment area. Designating the area separately will give them a classification consistent with the nature and severity of their overall air quality problem and will facilitate a more timely attainment finding.

Southern Inyo County

Jurisdictional Boundaries:

Inyo County falls under the jurisdiction of the Great Basin Unified Air Pollutio n Control District (GBUAPCD). Whereas Inyo County attained the previous 8

- hour
standard,

concentrations violate the revised ozone standard. Because of the

transport

- impacted nature of the air quality problem in Southern Inyo County, ARB staff recommends limiting the extent of the nonattainment area.

## 11

Geography / Topography:

Inyo County i s the second largest county in California

, encompassing over
10,000 square miles of varied terrain (refer to Figure 3). Within its borders lies the highest point in the continental United States, Mount Whitney, towering nearly 14,500 feet above sea level. Less than 100 miles away is Death Valley. Its lowest point, near Badwater, lies 282 feet below sea level. This is not only the
lowest point in the 48 contiguous states, but in the entire North American

continent. With these extremes in elevation come extremes in temperature and precipitation, both of which can impact air quality.

FIGURE 3

INYO COUNTY

Meteorology:

The geographical extremes of Inyo County provide for extremes in weather. The southern portion of the County is a high desert area with a typical desert climate. Summers are hot, while winters are cool. Maximum daily temperatures during the summer months are frequently well over 100 degrees Fahrenheit. What little
rainfall does occur, generally falls during the winter months. On ave rage

, rainfall
in the Death Valley area is less than 2 inches per year.

## 12

Information about ozone concentrations in Inyo County are based on data for Death Valley, Bishop, and the Trona air monitoring site

, which is just south of the Inyo County line in San Bernardino County. Some additional information is based on back trajectories constructed for a transport assessment.

Similar to Northeast San Bernardino County, Southern Inyo County is rural in nature with few ozone precursor emissions sources. Because the area lacks significant emissions sources capable of generating ozone locally, ozone concentrations measured in Southern Inyo County reflect the impact of long range transport. Based on general wind patterns, Southern Inyo County is

downwind of two major emission s source areas: the South Coast Air Basin and

the San Joaquin Valley Air Basin.

General wind patterns suggest that ozone is transported into Southern Inyo County from the south to southwest. This transported ozone travels northwar d, up valleys bounded by tall north

- south mountain ranges. The extent of this transport is limited by tall mountains that are transverse to these north

- south ranges. These transverse ranges represent the northern extent of transported

airflow. When air pollutants reach this point, they disperse vertically upslope,
and concentrations are lowered considerably. Although there are several towns

, such as Lone Pine and Bishop, that are located north of the recommended Southern Inyo County ozone nonattainment area

, there is no evidence that emissions from these areas are transported south, thereby impacting Southern Inyo County.

The extent of airflow into Southern Inyo County is limited by terrain. Similarly, federal hydrologic units are defined by terrain. These water drainage units generally follow the crests of mountain ranges. Hydrologic units are defined in a manner similar to the way air basins are defined, because water drainage is constrained by the same geographic features as airflow. As a result , hydrologic units provide an appropriate basis for defining the extent of ozone transport impacts in Southern Inyo County.

Air Quality Data:

There is only one ozone monitor in Inyo County for which complete

, quality

assured data are available. This monitor is located within the bounds of Death
Valley National Park. The design value based on 2006 through 2008 data is

0.081 parts per million, which exceeds the standard by 8 percent. The design value for Death Valley is similar to that for Trona in Sa n Bernardino County (0.080 ppm) and the China Lake area of Kern County (0.081 ppm). Both of these areas are located near Inyo County’s southern boundary

, and both are highly
impacted by transport, as well.

Figure 4 shows a trend line for design values at Death Valley since 1998. There has been little change in the trend over the years. Similar to the desert areas of

## 13

southern California, Southern Inyo County is impacted by transport from the South Coast and southern San Joaquin Valley areas.

Althou gh air quality in these upwind areas has improved over the years, the same degree of improvement has not been seen in downwind areas. However, trends in downwind areas are expected to improve with the implementation of control strategies emphasizing great er NOx reductions.

FIGURE 4

Ozone Design Values for

Death Valley National Park in Southern Inyo County

0.000 0.020 0.040 0.060 0.080 0.100 0.120 0.140 0.160

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Ozone DV (ppm)



## Population Density and Degree of Urbanization; Growth Rates and Patterns; and Traffic and Commuting Patterns:

While population density is relatively sparse throughout Inyo County, it is even more spread o ut in the southern portion. The GBUAPCD estimates only

0.22 people per square mile in the recommended Southern Inyo County nonattainment area. Over time, this area has actually seen a decrease in
population, from 3,473 people in 1990 to 3,117 people in 2 000. This represents

an overall decrease of about 10 percent , and t he population is not expected to grow significantly in the next several years. Although there are several roadways carrying traffic through Southern Inyo County, em issions related to commute s within the area are not significant be cause of the low population a nd scattered

nature of development with in the area.

## 14

Emissions Data and Level of Emission Controls

Emissions in Southern Inyo County are very low in comparison to the upwind South Coast and San Joaquin Valley air basins. As shown in Figure 3, there are only a handful of industrial stationary sources in Southern Inyo County.

Emissions from these sources total 181 tons per year of NOx, and there are no

measurable ROG emissions. In addition to stationary sources, there are several highways traversing Inyo County that contribute mobile source emissions.

Overall, countywide emissions for Inyo County total 1,699 tons per year of NOx
and 2,184 tons per year of ROG . Since 1990, there has been a 21 percent reduction in countywide NOx emissions and a 9 percent reduction in ROG
emissions. The statewide strategy will continue to reduce overall emissions in

the future. These future emission reductions will place great er emphasis on NOx reductions. Photochemical modeling shows that a greater emphasis on NOx reductions will have a greater benefit in terms reducing ozone concentrations in downwind, transport

- impacted areas such as Southern Inyo County.

Summary and Re commendation:

Inyo County is one of the largest counties in the nation, and encompasses a variety of landscapes

, from high mountain peaks to below sea level deserts. The revised ozone standard is exceeded in the southern portion of the County, which

has a n extremely low population and lacks significant industrial emissions sources. While the presumptive boundary for the nonattainment area would include all of Inyo County, ARB recommends a smaller nonattainment area because of the diversity of the area’s g eography and the nature of the ozone
impact.

Previous studies suggest that ozone concentrations at the Death Valley site are substantially impacted by transport. Wind flow into the southern portion of the County is generally from the south to southwest , carrying pollutants and emissions from the highly urbanized South Coast and southern San Joaquin Valley air basins into Southern Inyo County. Although Death Valley is the only monitoring site in Southern Inyo County, data are also collected at the Trona site

in San Bernardino County and in the China Lake area of Kern County. These sites are close to the southern boundary of Inyo County and suggest that exceedances are likely to occur throughout Southern Inyo County.

The recommended boundary for Southern Inyo County is based on federal hydrologic units. Hydrologic units are based on topography and water drainage, similar in many respects to the way California’s air basins are defined. Therefore, it is appropriate to use them in defining the nonattain ment area boundary, since mountainous terrain affects the transport and mixing depth of pollution. In addition, hydrologic units have been used in the past, to define ozone designation areas. ARB staff recommends the Southern Inyo County

## 15

ozone nonattainm ent area comprise the Inyo County portions of federal hydrologic units 16060015, 18090202, 18090203, 18090204, and 18090205.
These units cover not only the areas exceeding the standard, but also the extent of the region expected to be impacted by transport from the m ajor upwind urban

areas.

Eastern San Luis Obispo County

Jurisdictional Boundaries:

San Luis Obispo County is part of California’s South Central Coast Air Basin. Air quality control in the County is under the jurisdiction of the San Luis Obispo County Ai r Pollution Control District (SLOAPCD)

Geography / Topography:

Although San Luis Obispo County is generally considered a coastal area, this generalization applies only to the western portion of the County (refer to Figure 5 ). This western portion incl udes the major cities in the County such as San Luis Obispo, Atascadero, and Paso Robles. As one moves inland, the coastal plain gives way to the mountains of the Coast Ranges, interspersed with

FIGURE 5

SAN LUIS OBISPO COUNTY

## 16

a se ries of valleys and high plains which range in elev ation from about 2000 to

more than 5 0 00 feet

. These rural, higher el evation areas separate San Luis Obispo County from the San Joaquin Valley. Although Eastern San Luis Obispo County is sparsely populated, there are scattered settlements and public
facilities, such as schools. This area also includes Carrizo Plains Nati onal
Monument, with grinding rocks and rock paintings reflecting the historic Native American population.

Me teorology:

San Luis Obispo County is a meteorologically diverse region. To the west, high

summer temperat ures average in the low to mid 60s. Toward the middle of the County, high summer temperatures average in the low to high 70s. In contrast to
both these areas, Eastern San Luis Obispo County sees high summer
temperatures, averaging in the 90s, and the mou ntains separating the eastern portion of the County from the western portion effectively block the tempering

influence of the ocean.

In terms of general wind patterns, Eastern San Luis Obispo is downwind of both

the San Joaquin Valley and the San Franci sco Bay Area air basins. Previous ARB transport assessments found these areas to have an overwhelming impact on ozone concentrations in San Luis Obispo County.

Air Quality Data:

Ozone data are available for two sites in Eastern San Luis Obispo County:

Carrizo Plains and Red Hills. Table 4 includes design values, b ased on data for
2006 through 2008, for sites in both the eastern and western portions of San Luis Obispo County. Values for the eastern sites are 12 to 17 percent above the level

of the sta ndard, whereas values for the western sites attain the standard.

TABLE 4

8

- HOUR OZONE DESIGN VALUES FOR VARIOUS PORTIONS OF

SAN LUIS OBISPO COUNTY BASED ON 2006 THROUGH 2008 DATA

SITE / COUNTY PORTION DESIGN VALUE (ppm) PERCENT ABOVE

STANDARD

Carriz o Plains / Eastern San Luis Obispo 0.084 12%

Red Hills / Eastern San Luis Obispo 0.088* 17%

Paso Robles / Western San Luis Obispo 0.068 0%

Atascadero / Western San Luis Obispo 0.068 0%

* Design Value based on 2 years of data (2007

- 2008).

## 17

Because lon

g

- term data are not available for either Carrizo Plains or Red Hills, design value trends are not available. However, long

- term trends for high sites in the western portion of the County and for the upwind air basins are plotted in Figure 6 . The trends f or the San Luis Obispo sites, which are also impacted by transport from the San Francisco Bay Area and San Joaquin Valley air basins, track fairly well with the upwind areas and show similar rates of improvement. We expect sites in Eastern San Luis Obispo County would show similar trends

.

FIGURE 6

Ozone Design Values for

Western San Luis Obispo Sites and

Upwind Air Basins

0.00 0.02 0.04 0.06 0.08 0.10 0.12

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Ozone DV (ppm)

Paso Robles Atascadero

San Francisco Bay Area San Joaquin Valley



## Population Density and Degree of Urbanization; Growth Rates and Patterns; and Traffic and Commuting Patterns:

More than 250,000 people reside in San Luis Obispo County, with the majority living in the w estern portion of the County. Overall, more than 95 percent of the County’s population lives in Western San Luis Obispo County. Those that live in

Eastern San Luis Obispo County are scattered throughout the area. Between

1990 and 2000, the total number of people in the eastern portion of the County actually decreased, and the SLOAPCD expects little growth in the area over the next several years. In contrast, the number of people living in the western
portion increased by about 15 percent between 1990 an d 2000. E m issions

related to commute s within the area are not significant be cause of the low
population a nd scattered nature of development

.

## 18

Emissions Data and Level of Emission Controls:

Emissions in Eastern San Luis Obispo County are very low. The SLOAPCD

estimates a total of 2.2 tons per year of ROG and 4.3 tons per year of NOx in the eastern portion of the County. These amounts are less than 1 percent of the total countywide ROG and NOx emissions. There are limited mobile source emissions from several highways traversing the eastern County area. Emissions from these sources are not expected to significantly impact ozone concent rations

in Eastern San Luis Obispo County. Overall, emission sources located throughout San Luis Obispo County are subject to the rules and regulations of
the SLOAPCD. In addition, mobile source emissions will continue to be reduced

under the statewide s trategy.

Summary and Recommendation:

San Luis Obispo County comprises coastal, as well as inland areas. However, the revised ozone standard is violated only at the inland sites, which are high elevation sites located in the rural, eastern portion of th e County. This portion of the County is sparsely populated and lacks emissions sources. The design value

for the eastern area is 0.084 ppm, measured at Carrizo Plains (Red Hills has a higher value, 0.088 ppm, but this value is based on only two years of data). Sites in Western San Luis Obispo County, as well as in counties to the north and to the

south, all attain the standard.

The high elevation sites in Eastern San Luis Obispo County were originally sited
to provide information on transport impacts from upwind urban areas. Previous studies have shown that ozone and ozone precursor emissions from the

San Joaquin Valley are transported west, impacting Eastern San Luis Obispo County, including the Carrizo Plains and Red Hills sites. Ozone concentratio ns can also be impacted by transport south from the San Francisco Bay Area. Because violations occur only at elevated sites in the eastern County, ARB recommends limiting the nonattainment area to Eastern San Luis Obispo County

, which reflect s the extent of the County influenced by transport sufficient to cause

violations of the federal standard

.

Pinnacles National Monume nt

Jurisdictional Boundaries:

Nearly all of Pinnacles National Monument is located in San Benito County, with a small portion in Monterey County. Air quality control throughout San Benito

C o unty fall s u nder the jurisdiction of the Monterey Bay Unified Air Pollution

Control Distri ct (MBUAPCD). All sites within the MBUAPCD region attained the previous 8

- hour standard. The monitor at Pinnacles is the only one that violates

the revised standard.

## 19

Geography / Topography:

Pinnacles National Monument is located in an area of rugged terrain in

California’s North Central Coast Air Basin (refer to Figure 7 ). It lies about

40 miles inland from the Pacific Ocean, just east of the Salinas Valley, and about

80 miles south of the San Francisco Bay Area. The monument is in the southern

port ion of the Gabilan Mountains, which are part of California's Central Coast Range. Elevations within the Monument boundaries range from 824 feet to 3,304 feet at the top of North Chalone Peak

. The landscape includes the spectacular remains of an ancient v olcano. Massive monoliths, spires,

sheer

- walled canyons, and talus passages have been created through millions of years of erosion, faulting, and tectonic plate movement. Established in 1908,

the Monument has increased by bits and pieces to its present size of about

26,000 acres. It boasts o ver 30 miles of trails, but has no overnight facilities.

FIGURE 7

PINNACLES NATIONAL MONUMENT IN SAN BENITO COUNTY

Meteorology:

Pinnacles National Monument has a Mediterranean climate with hot, dry

summers and cool, moderately wet winters. Although the Monument is only

40 miles inland from the Pacific Ocean, the Santa Lucia Mountains to the west

## 20

strongly modify the ocean influence before it reaches Pinnacles. As a result, summer temperatures at Pinnacles m ight range from 50 degrees Fahrenheit at night to 100 degrees during the day, while those near the coast are a fairly steady 60 degrees. Similarly, winter temperatures at Pinnacles often drop below freezing while coastal temperatures remain moderate. Ave rage rainfall at Pinnacles is 16 inches per year, with most of it occurring between January and March. Small amounts of snow fall at the higher elevations between

mid

- December and January.

Based on general wind patterns, Pinnacles National Monument is do wnwind of

the San Francisco Bay Area, which has significant emissions sources. Pollutants and emissions from the Bay Area are transported aloft, impacting concentrations at high elevations in the Pinnacles area. Previous transport assessments found

the t ransport contribution from the San Francisco Bay Area can have an
overwhelming impact on ozone concentrations measured at Pinnacles.

Air Quality Data:

The monitor at Pinnacles National Monument was sited to measure high elevation transport from the San Francisco Bay Area. The location is isolated

and remote. Ozone concentrations measured at Pinnacles exceed the revised

federal 8

- hour ozone standard, with a design value of 0.079 ppm. In contrast, design values for other sites in the surrounding nor th central coast region are all well below the level of the standard, ranging from 0.052 ppm to 0.069 ppm. All of

these sites are located at lower elevations.

The design value trend for Pinnacles is shown in Figure 8

. With the exception of

2008, the design value for Pinnacles has shown an overall downward trend since 1998. In fact, the 2006 and 2007 design values for this site (0.075 ppm and

0.074 ppm, respectively) show attainment. The higher value for 2008 likely reflects the impact of wildfi res that burned throughout the State during the summer of 2008. If the impacted days were removed from consideration, the 2008 design value would be more consistent with values for previous years.
However, the area would still be nonattainment.

The trend for Pinnacles closely follows the trend for the San Francisco Bay Area, although at a slightly lower level. Previous transport study indicates that
exceedances measured at Pinnacles are overwhelmingly impacted by transport

aloft from the Bay Area. Although the San Francisco Bay Area does not yet attain the standard, design values for Bay Area sites have decreased at a rate

similar to those for Pinnacles. As emissions in the San Francisco Bay Area
continue to decrease, ozone concentration s in downwind areas such as
Pinnacles will also continue to improve.

## 21 F IGUR E 8

Population Density and Degree of Urbanization; Growth Rates and Patterns; and Traffic and Commuting Patterns:

There is no permanent population living at Pinnacles National Monument, and

there are no overnight accommodations for those visiting the monument.
Because there are no roads travelling through the Monument, traffic is limited to those visiting the Monument for day use.

Emissions Data and Level of Emission Controls

With the exception of the few roads, there are no significant emissions sources

located within Pinnacles National Monument. As a resu lt, the area lacks emissions for locally generating ozone. Previous analyses indicate that ozone

concentrations measured at the Pinnacles monitor are attributable to the transport of pollutants and emissions from the San Francisco Bay Area. Ozone

concent rations at Pinnacles should continue to decrease, with continued implementation of upwind district controls and the statewide strategy. Ozone Design Values for

Pinnacles National Monument and

San Francisco Bay Area

0.00 0.02 0.04 0.06 0.08 0.10

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Ozone DV (ppm)

Pinnacles National Monument San Francisco Bay Area

## 22

Summary and Recommendation:

The Pinnacles monitor is an elevated site (1000 feet) located in an area of complex terra in within the boundaries of Pinnacles National Monument. With the
exception of a few roads, there are no local ozone precursor emissions sources. In addition, there are no permanent residents

, and overnight stays are not

allowed within the Monument bound aries. Ozone exceedances in the North Central Coast Air Basin are measured only at Pinnacles. All other sites in the surrounding areas attain the standard , with design values ranging from 0.052 to

0.069 ppm in the surrounding three

- county area (Monterey, Santa Cruz, and

San Benito counties) . Furthermore, the violations at Pinnacles are attributable to transport from the San Francisco Bay Area, which will continue to be designated

as nonattainment.

ARB recommends a focussed nonattainment area, limited to that portion of

Pinnacles National Monument located within San Benito County. Using the Monument boundary provides an easily identifiable nonattainment area, and it adequately reflects the region impacted by the u pwind urban area.

Tuscan Buttes

J urisdictional Boundaries:

Tuscan Buttes is located in eastern Tehama County in the northern Sacramento
Valley. All of Tehama County is under the jurisdiction of the Tehama County Air

Pollution Control District.

Geography / Topography:

As shown in Figu re 9

, Tuscan Buttes is an isolated, elevated area in the Upper Sacramento Valley, where the majori ty of the land is near sea level

. Located

about 10 miles northeast of Red Bluff, Tuscan Buttes is a narrow, small ridge on the eastern side of the Valley. T he area at the top of the B uttes stands above

1800 feet elevation.

## 23 FIGURE 9

TUSCAN BUTTES IN TEHAMA COUNTY

Meteorology:

Tuscan Buttes exhibits the typical climate pattern of the Sacramento Valley, with hot, dry summers and cooler, wetter winters. In terms of air quality, the Buttes

are impacted by transport from the Sacramento urban area. Based on general wind patterns, this area is downwind of significant emissions sources within the Sacramento Metro Area. Previous transport assessments found th at the transport contribution from the Sacramento Metro Area to the Upper Sacramento Valley can be overwhelming. Because there are no local population or emissions

sources, ozone concentrations measured at Tuscan Buttes are attributable to
transport.

Ai r Quality Data:

Figure 10 shows the design value trends for Tuscan Buttes , as well as for the upwind Sacramento Metro Area. The graph also shows the trend line for

Sutter Buttes, another high elevation, transport dominated site in the Upper

Sacramento Va lley. The trends for both Tuscan Buttes and Sutter Buttes are nearly identical. Both track well with the trend for the Sacramento Metro Area, illustrating the importance of transport at the two locations.

## 24 FIGURE 10

Ozone Design Values for

Tuscan Buttes, Sutter Buttes, and

Sacramento Metro Nonattainment Area

0.00 0.02 0.04 0.06 0.08 0.10 0.12

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Ozone DV (ppm)

Tuscan Buttes Sutter Buttes Sacramento Metro Area



## Although all three areas show g eneral improvement over the years, the values for 2008 are slightly higher than for previous years. These higher values likely reflect the impact of wildfires that burned throughout California during the

summer of 2008. If the fire

- impacted days were rem oved, the design values for
2008 would be lower, but the areas would still be nonattainment.

Because there is no population in either the Tuscan Buttes or Sutter Buttes
areas, ozone concentrations measured at these sites do not represent population

e xposure. In contrast to these sites, design values for surrounding sites that are located in populated areas, such as the Red Bluff site in Tehama County and

sites in the populated areas of Colusa, Glenn, and northern Sutter counties,

show attainment of the revis ed standard.

Population Density and Degree of Urbanization; Growth Rates and Patterns; and Traffic and Commuting Patterns:

There is no population living at Tuscan Buttes or in the surrounding local area. This is not expected to change in the next severa l years. Access to the area is

limited, and traffic

- related emissions are insignificant

.

Emissions Data and Level of Emission Controls

There are virtually no ozone precursor emissions sources in the Tuscan Buttes area. The only development on the Buttes is a radio facility and a fire lookout.

## 25

Access to these facilities is very li mited. The site is dominated by transport from the Sacramento Metro area, and attainment will depend on upwind district
controls and the statewide strategy.

Summary and Recommendation:

There are two monitors in Tehama County. The first site, Red Bluff

- Oak Street,

is located in the town of Red Bluff at an elevation of 322 feet. The design value for this site reflects population exposures and meets the revised standard . In contrast, the design value for the Tuscan Buttes site violates the standard. The re

are no population or emissions in the Tuscan Buttes area. Ozone concentrations measured at the site are dominated by transport from the Sacramento Metro

Area.

Located at an elevation of 1,877 feet, the Tuscan Buttes monitor is similar to the

Sutte r Buttes monitor in Sutter County. Both of these monitors were sited to study high

- elevation transport of pollutants from the Sacramento Metro Area into

the U pper Sacramento Valley . T here are no pollution sources or populated

areas near eit her site. In both cases, d esign values for low er elevation sites in
the surrounding populated areas all attain the standard , lending additional support to the argument that the ozone problems at the elevated sites are unique

and isolated.

Sutter Butte s is currently designated as nonattainment, and the nonattainment

area includes the immediate area above 200 0 feet elevation

. Because of the elevated location and lack of population exposure at the Tuscan Buttes site, ARB

recommends the geographic scope o f th is nonattainment area be limited to that portion of the Tuscan Buttes area with an elevation of 1800 feet or more. This approach is c onsistent with the approach U.S. EPA used in designating the

Sutter Buttes ozone nonattainment area.

Eastern Kern County

Jurisdictional Boundaries:

Kern County is located in two different air basins. The western portion of the County is located in the San Joaquin Valley Air Basin, while the eastern portion is
located in the Mojave Desert Air Basin (refer to Figur e 1 1 )

. The eastern portion of the County falls under the jurisdiction of the Kern County Air Pollution Control District. Currently, the northeast corner of Eastern Kern County , which coincides with the Kern County portion of federal hydrologic unit # 180 90205, is designated

as attainment for the old federal 8

- hour standard. In contrast, the remainder of Eastern Kern County is designated as nonattainment.

## 26 FIGURE 1 1

EASTERN KERN COUNTY

Geography / Topography:

Eastern Kern County occupies the north western portion of the Mojave Desert, as well as portions of the Tehachapi Mountains and the southern end of the Sierra

Nevada. The ozone monitors in Eastern Kern County are located in t he desert portions of the region , which are classified as high desert . Elevations in this area

range from about 2000 to 5000 feet above sea level.

Meteorology:

Violations of the revised ozone standard are measured at two sites in the desert portion of Eastern Kern County. Th is desert region has a typical desert climate,

wi th hot dry summers and cool winters with little rainfall. In the southern part of Eastern Kern County, maximum summer temperatures average 94 degrees Fahrenheit, and rainfall averages 6 inches per year. Values in the northeast

corner (Indian Wells Valley area) are a little higher, with maximum summer temperatures averaging 100 degrees and rainfall averaging 7 inches each year.

Based on general wind patterns, Eastern Kern County is downwind of two major

urban source areas: the South Coast Air Basin and the San Joaquin Valley Air Basin. As a result, ozone concentrations throughout Eastern Kern County are

## 27

impacted by long range transport from these areas. Previous transport assessments show that ozone concentrations in Eastern Kern County can be

overwhel med by transport from the upwind areas.

Air Quality Data:

Ozone data are available for a site at the China Lake Naval Air Weapons Station
in the Indian Wells Valley and a site at Mojave

- Poole Street in the current nonattainment area. The design val ue for China Lake is 0.081 ppm, while the design value for Mojave is 0.086 ppm. Both of these values violate the revised

standard.

As mentioned previously, ozone air quality in Eastern Kern County is significantly impacted by transport from both the San Joaquin Valley and the South Coast a ir

b asin s

. Figure 1 2 shows the trend in design values for Mojave, as well as for the

San Joaquin Valley and South Coast Air Basin (long

- term trend data are not available for the China Lake site) . The trends show that although the design value for Mojave is lower, it tracks well with the South Coast and San Joaquin Valley trends. Because of the overwhelming transport impact, ozone air quality
in Mojave has decreased at a rate similar to that in the upwind areas. Altho ugh China Lake is not included on the graph , t his site is also impacted by transport, and we would expect the trend to be similar to that for Mojave , but at a lower

level, overall

.

FIGURE 1 2

Ozone Design Values for Eastern Kern County

and Upwind Air Basins

0.000 0.020 0.040 0.060 0.080 0.100 0.120 0.140 0.160

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Ozone DV (ppm)

Mojave-Poole South Coast Air Basin

San Joaquin Valley

## 28

Population Density and Degree of Urbanization; Grow th Rates and Patterns; and Traffic and Commuting Patterns:

Several towns are scattered throughout Eastern Kern County. The largest one in
the Indian Wells Valley area is Ridgecrest. This town grew up around the China Lake Naval Air Weapons Center. Over all, population in all of E astern Kern

C ounty is small, compared with that in the South Coast and San Joaquin Valley areas. The total Eastern Kern County population in 2005 was about 132,000. The increase in population has also been small, increasing onl y 13 percent

between 1995 and 2005. Because of the limited population, overall local

, traffic

- related emissions are not expected to be significant

.

Emissions Data and Level of Emission Controls

Relative to the South Coast and San Joaquin Valley air basins, ozone precursor emissions in Eastern Kern County are insignificant. There are only a handfull of stationary

sources (refer to Figure 1 1 ), and nearly all of these are located in the portion of Eastern Kern County that is already designated as nonattainment. In addition to these stationary sources, several highways traverse the region, carrying traffic in and ou t of the Eastern Kern County area

. Because of the sparse population and limited emissions sources, attainment in Eastern Kern County is dependent on emissions reductions in the upwind districts and from the
statewide strategy.

Summary and Recommendati on:

Indian Wells Valley is a high desert area in the northeast corner of Kern County. It includes the China Lake Naval Air Weapons Station and the town of Ridgecrest. Similar to the rest of Eastern Kern County, Indian Wells Valley is
sparsely populated and has few significant emissions sources. The design value for Indian Wells Valley (0.081 ppm) is similar to the design value for the current Eastern Kern County nonattainment area (0.086 ppm). Furthermore, previous

studies have shown that ozone concent rations in both of these areas are overwhelmingly impacted by transport from the San Joaquin Valley and South

Coast air basins.

Because both areas are similar in terms of air quality, population, emissions, and
transport impacts, ARB recommends the cur rent Eastern Kern County nonattainment area be expanded to include the Indian Wells Valley area. As a result, the entire portion of Kern County within the Mojave Desert Air Basin would be included in the Eastern Kern County ozone nonattainment area.

## 1 ENCLOSURE 4

STATE OF CALIFORNIA BOUNDARY RECOMMENDATIONS

FOR NEW NONATTAINMENT AREAS

UNDER THE 2008 FEDERAL 8

- HOUR OZONE STANDARD

NORTHEAST SAN BERNARDINO COUNTY

That portion of San Bernardino County that lies north and east of a line described

as follows: latitude 35 degrees, 10 minutes north and longitude 115 degrees,

45 m inutes west

.

SOUTHERN INYO COUNTY

That portion of Inyo County that lies within the bounds of H ydrologic Unit

Number 16060015, 18090202, 18090203, 18090204, and 18090205.

EASTERN SAN LUIS OBISPO COUNTY

That portion of San Luis Obispo County that lies east of a line described as follows: Beginning at the San Luis Obispo County / Santa Barbara County
boundary and running north along 120 degrees 24 minutes longitude to the

intersection with 35 degrees 27 minutes latitude; east along 35 degrees

27 minutes latitude to the intersection with 120 degrees 18 minutes longitude;
then north along 120 degrees 18 minutes longitude to the San Luis Obispo County / Monterey County bo undary.

PINNACLES NATIONAL MONUMENT (SAN BENITO COUNTY)

That portion of San Benito County that lies within the boundary of Pinnacles
National Monument as it existed on February 26, 2009.

TUSCAN BUTTES

(TEHAMA COUNTY)

That portion of the immediate T uscan Buttes area at or above 1,800 feet in

elevation.

## 2

EASTERN KERN

COUNTY

That portion of Kern County that lies east and south of a line described as

follows: Beginning at the Kern County / Los Angeles County boundary and
running north and east along t he northwest boundary of the Rancho La Liebre Land Grant to the point of intersection with the range line common to Range 16 West and Range 17 West, San Bernardino Base and Meridian; north along the range line to the point of intersection with the Rancho E l Tejon Land Grant boundary; then southeast, northeast, and northwest along the boundary of the Rancho El Tejon Grant to the northwest corner of Section 3, Township 11 North, Range 17 West; then west 1.2 miles; then north to the Rancho El Tejon Land

Grant boundary; then northwest along the Rancho El Tejon line to the southeast corner of Section 34, Township 32 South, Range 30 East, Mount Diablo Base and Meridian; then north to the northwest corner of Section 35, Township 31 South, Range 30 East; then northe ast along the boundary of the Rancho

El Tejon Land Grant to the southwest corner of Section 18, Township 31 South, Range 31 East; then east to the southeast corner of Section 13, Township 31 South, Range 31 East; then north along the range line common to R ange 31 East and Range 32 East, Mount Diablo Base and Meridian, to the northwest corner of Section 6, Township 29 South, Range 32 East; then east to the southwest corner of Section 31, Township 28 South, Range 32 East; then north along the range line commo n to Range 31 East and Range 32 East to the northwest corner of Section 6, Township 28 South, Range 32 East, then west to the southeast corner of Section 36, Township 27 South, Range 31 East, then
north along the range line common to Range 31 East and Rang e 32 East to the

Kern County /

Tulare County boundary.

## 1 ENCLOSURE 5

SUMMARY OF DATA AND FEDERAL 8

- HOUR OZONE DESIGN VALUES

FOR CALIFORNIA SITES BASED ON 2006 THROUGH 2008 DATA

Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.082 0.085 0.077 0.081 Inyo Death Valle y Natl Monument Valid Days 347 351 320

Alpine NO MONITORS Great Basin Valleys

Mono NO MONITORS

4 th High 0.062 0.057 0.068 0.062 Lake County Lake Lakeport

- Lakeport Blvd Valid Days 360 354 328

4 th High 0.069 0.070 0.072 0.070 El Dora do South Lake Tahoe

- Airport

Road Valid Days 160 169 151 Lake Tahoe

Placer NO MONITORS

4 th High 0.089 0.078 0.093 0.086 Kern Mojave

- 923 Poole Street Valid Days 357 358 188

4 th High 0.098 0.091 0.095 0.094 Los Angeles Lancaster

- 43301 Division

Street Valid Days 363 357 360

4 th High 0.057 0.066 0.067 0.063 Riverside Blythe

- 445 West Murphy Street Valid Days 361 284 237

4 th High 0.086 0.084 0.090 0.086 Barstow Va lid Days 344 356 364

4 th High 0.095 0.098 0.098 0.097 Hesperia

- Olive Street Valid Days 358 356 362

4 th High 0.103 0.104 0.105 0.104 Joshua Tree

- National

Monument Valid Days 348 342 322

4 th High 0.097 0.093 0.099 0.096 Phelan

- Beekley Rd & Phelan

Rd' Valid Days 363 356 365

4 th High 0.080 0.077 0.084 0.080 Trona

- Athol and Telegraph Valid Days 360 351 339

4 th High 0.091 0.087 0.089 0.089 Mojave Desert

San Bernardino

Victorville

- 14306 Park Avenue Valid Days 363 362 359

4 th High 0.085 0.073 0.101 0.086 Amador Jackson

- Clinton Road Valid Days 363 344 265

4 th High 0.098 0.076 0.094 0.089 Calaveras San Andreas

- Gold Strike Road Valid Days 364 356 267

4 th High 0.099 0.093 0.10 2 0.098 Cool

- Highway 193 Valid Days 183 181 150

4 th High 0.075 0.075 0.078 0.076 Echo Summit Valid Days 148 135 135

4 th High 0.097 0.085 0.106 0.096 El Dorado

Placerville

- Gold Nugget Way Valid Days 363 333 272

4 th Hi gh 0.080 0.083 0.089 0.084 Mountain

Countie s

Mariposa Jerseydale

- 6440 Jerseydale Valid Days 175 181 183

## 2 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.084 0.087 0.094 0.088 Mariposa (continued) Yosemite NP

- Turtleback Dome Valid Days 292 334 317

4 th High 0.096 0.088 0.091 0.091 Grass Valley

- Litton Building Valid Days 328 365 247

4 th High 0.076 0.071 0.066 0.071 Truckee

- Fire Station Valid Days 225 281 265

4 th High 0.08 9 0.082 0.091 0.087 Nevada

White Cloud Mountain Valid Days 162 182 153

4 th High 0.105 0.079 0.084 0.089 Placer Colfax

- City Hall Valid Days 346 356 338

4 th High 0.064 0.064 Plumas Quincy

- N Church Street Valid Days 229

4 th High 0.079 0.084 0.098 0.087 Tuolumne Sonora

- Barretta Street Valid Days 365 360 271 Mountain

Counties (continued)

Sierra NO MONITORS

4 th High 0.060 0.059 0.060 0.059 Carmel Valley

- Ford Road Valid Days 364 365 332

4 th High 0.054 0.06 0.057 King City

- 415 Pearl Street Valid Days 215 304

4 th High 0.063 0.054 0.058 King City

- 750 Metz Road Valid Days 360 134

4 th High 0.054 0.053 0.060 0.055 Monterey

Salinas

- #3 Valid Days 358 354 322

4 th High 0.071 0.068 0.068 0.069 Hollister

- Fairview Road Valid Days 359 352 329

4 th High 0.078 0.075 0.086 0.079 San Benito

Pinnacles National Monument Valid Days 355 361 324

4 th High 0.052 0.049 0.056 0.052 Davenport Valid Days 364 362 322

4 th High 0.054 0.053 0.057 0.054 Santa Cruz

- 2544 Soquel Ave Valid Days 358 358 329

4 th High 0.062 0.059 0.064 0.061 Scotts Valley

- Scotts Valley Dr Valid Days 361 361 332

4 th High 0.054 0.054 0.058 0.055 North Central

Coast

Santa Cruz

Watsonville

- Airport Boulevard Valid Days 363 364 334

4 th Hi gh 0.046 0.049 0.047 Humboldt Eureka

- Jacobs Valid Days 17 308 347

4 th High 0.060 0.053 0.061 0.058 Ukiah

- E Gobbi Street Valid Days 356 352 302

4 th High 0.049 0.046 0.045 0.046 North Coast

Mendocino

Willits

- 899 S Main Street Valid Days 351 358 149

## 3 Year

Basin Na me County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.056 0.060 0.055 0.057 Sonoma Healdsburg

- Municipal Airport Valid Days 338 341 271

Del Norte NO MONITORS North Coast (continued)

Trinity NO MONITORS

4 th High 0.067 0.060 0.058 0.061 Siskiyou Yreka

- Foothill Drive Valid Days 318 332 264

Lassen NO MONITORS Northeast Plateau

Modoc NO MONITORS

4 th High 0.076 0.074 0.080 0.076 Chico

- Manzanita Avenue Valid Days 360 363 262

4 th High 0.089 0.083 0.084 0.085 Butte

Paradise

- 44 05 Airport Road Valid Days 361 364 269

4 th High 0.069 0.066 0.072 0.069 Colusa Colusa

- Sunrise Blvd Valid Days 357 361 269

4 th High 0.059 0.069 0.067 0.065 Willows

- 720 N Colusa Street Valid Days 1 06 361 271

4 th High 0.063 0.063 Glenn

Willows

- E Laurel Street Valid Days 252

4 th High 0.098 0.079 0.095 0.090 Auburn

- Dewitt

- C Avenue Valid Days 330 347 351

4 th High 0.094 0.082 0.094 0.090 Placer

Roseville

- N Sunrise Blvd Valid Days 363 350 271

4 th High 0.087 0.078 0.082 0.082 Elk Grove

- Bruceville Road Valid Days 357 359 330

4 th High 0.102 0.090 0.114 0.102 Folsom

- Natoma Street Valid Days 358 354 327

4 th High 0.092 0.071 0.0 72 0.078 North Highlands

- Blackfoot Way Valid Days 356 341 245

4 th High 0.077 0.077 0.080 0.078 Sacramento

- 3801 Airport Road Valid Days 311 299 201

4 th High 0.093 0.081 0.087 0.087 Sacramento

- Del Paso Manor Valid Days 349 362 323

4 th High 0.08 4 0.073 0.081 0.079 Sacramento

- T Street Valid Days 351 342 292

4 th High 0.104 0.080 0.102 0.095 Sacramento

Sloughhouse Valid Days 214 208 212

4 th High 0.073 0.075 0.081 0.076 Anderson

- North Street Valid Days 327 365 274

4 th High 0.074 0.076 0.083 0.077 Lassen Vol NP

- Manzanita Lk Valid Days 353 362 316

4 th High 0.080 0.070 0.077 0.075 Sacramento
Valley

Shasta

Redding

- Health Dept Roof Valid Days 357 365 338

## 4 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.080 0.071 0.084 0.078 Solano Vacaville

- Ulatis Drive Valid Days 358 365 354

4 th High 0.090 0.077 0.088 0.085 Sutter Buttes

- S Butte Valid Days 184 183 153

4 th High 0.078 0.072 0.068 0.072 Sutter

Yuba City

- Almond Street Valid Days 352 343 264

4 th High 0.073 0.072 0.080 0.075 Red Bluff

- Oak Street Valid Days 330 357 319

4 th High 0.087 0.082 0.087 0.085 Tehama

Tuscan Butte Valid Days 183 184 146

4 th High 0.078 0.075 0.077 0.076 Davis

- UCD Campus Val id Days 358 359 258

4 th High 0.088 0.073 0.076 0.079 Yolo

Woodland

- Gibson Road Valid Days 365 363 356 Sacramento Valley (co ntinued)

Yuba NO MONITORS

4 th High 0.043 0.067 0.057 0.055 Brawley

- 220 Main Street Valid Days 91 89 14

4 th High 0. 078 0.083 0.078 0.079 Calexico

- East Valid Days 352 325 341

4 th High 0.068 0.087 0.087 0.080 Calexico

- Ethel Street Valid Days 362 353 363

4 th High 0.065 0.071 0.068 Calexico

- Grant Street Valid Days 356 205

4 th High 0.091 0.0 83 0.074 0.082 El Centro

- 9th Street Valid Days 331 349 362

4 th High 0.072 0.078 0.075 0.075 Niland

- English Road Valid Days 354 355 362

4 th High 0.086 0.085 0.077 0.082 Imperial

Westmorland

- W 1st Street Valid Days 355 353 360

4 th Hig h 0.085 0.087 0.088 0.086 Indio

- Jackson Street Valid Days 361 360 237

4 th High 0.079 0.076 0.084 0.079 Joshua Tree National Park Valid Days 270 281 129

4 th High 0.099 0.097 0.096 0.097 Salton Sea

Riverside

Palm Springs

- Fire Station Valid Days 354 360 241

4 th High 0.094 0.086 0.098 0.092 A lpine

- Victoria Drive Valid Days 357 358 301

4 th High 0.072 0.071 0.070 0.071 Camp Pendleton Valid Days 355 349 300

4 th High 0.065 0.070 0.074 0.069 Chula Vista Valid Days 357 351 299

4 th High 0.067 0.072 0.075 0.071 San Diego San Diego

Del Mar

- Mira Cos ta College Valid Days 364 362 305

## 5 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.076 0.073 0.082 0.077 El Cajon

- Redwood Avenue Valid Days 349 332 297

4 th High 0.078 0.075 0.089 0.080 Escondido

- E Valley Parkway Valid Days 352 355 291

4 th High 0.061 0.064 0.066 0.063 Otay Mesa

- Paseo International Valid Days 359 357 273

4 th High 0.061 0.060 0.063 0.061 San Diego

- 1110 Beardsley St Valid Days 362 330 291

4 th High 0.07 0.073 0.082 0.075 San Diego (continued) San Diego

(continued)

San Diego

- Overland Avenue Valid Days 354 357 296

4 th High 0.029 0.045 0.037 Berkeley

- 6th Street Valid Days 23 269

4 th High 0.069 0.055 0.061 0.061 Fremont

- Chapel Way Valid Days 358 352 271

4 th High 0.067 0.055 0.068 0.063 Hayward

- La Mesa Valid Days 244 242 182

4 th High 0.089 0.067 0.087 0.081 Livermore

- 793 Rincon Avenue V alid Days 361 361 270

4 th High 0.034 0.057 0.045 Oakland

- Davie Valid Days 60 268

4 th High 0.06 0.052 0.067 0.059 Alameda

San Leandro

- County Hospital Valid Days 243 243 175

4 th High 0.081 0.071 0.076 0.076 Bethel Island Road Valid Days 358 360 271

4 th High 0.085 0.071 0.078 0.078 Concord

- 2975 Treat Blvd Valid Days 360 360 270

4 th High 0.079 0.067 0.067 0.071 Pittsburg

- 10th Street Valid Days 357 356 271

4 th High 0.045 0.049 0.057 0.050 Contra Costa

San Pablo

- Rumrill Blvd Valid Days 353 356 265

4 th High 0.047 0.048 0.055 0.050 Marin San Rafael Valid Days 353 356 266

4 th High 0.064 0.055 0.067 0.062 Napa Napa

- Jefferson Avenue Valid Days 361 355 269

4 th High 0.044 0.047 0.049 0.046 San Francisco San Francisco

- Arkansas Street Valid Days 347 354 266

4 th High 0.051 0.052 0.058 0.053 San Mateo Redwood City Valid Days 354 357 266

4 th High 0.08 0.068 0.072 0.073 Gilroy

- 9th Street Valid Days 229 2 40 183

4 th High 0.085 0.059 0.074 0.072 Los Gatos Valid Days 363 363 273

4 th High 0.073 0.057 0.067 0.065 San Francisco
Bay Area

Santa Clara

San Jose

- Jackson Street Valid Days 329 352 269

## 6 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.088 0.070 0.071 0.076 San Martin

- Murphy Avenue Valid Days 238 239 182

4 th High 0.064 0.054 0.063 0.060 Santa Clara (continued) Sunnyvale

- 910 Ticonderoga Valid Days 243 243 183

4 th High 0.063 0.075 0.069 Benicia

- East 2nd Street Valid Days 270 266

4 th High 0.074 0.062 0.068 0.068 Fairfield

- Chadbourne Road Valid Days 242 241 183

4 th High 0.06 0.054 0.067 0.060 Solano

Vallejo

- 304 Tuolumne Street Valid Days 346 354 267

4 th High 0.049 0.047 0.059 0.051 San Francisco Bay Area (continued)

Sonoma Santa Rosa

- 5th Street Valid Days 362 357 269

4 th High 0.094 0.092 0.108 0.098 Clovis

- N Villa Avenue Valid Days 357 341 269

4 th High 0.101 0.094 0.108 0.101 Fresno

- 1st Str eet Valid Days 362 360 265

4 th High 0.085 0.079 0.093 0.085 Fresno

- Drummond Street Valid Days 359 357 241

4 th High 0.097 0.088 0.101 0.095 Fresno

- Sierra Skypark #2 Valid Days 355 359 262

4 th High 0.099 0.090 0.094 0.094 Fresno

Parlier Valid Days 339 356 231

4 th High 0.111 0.102 0.112 0.108 Arvin

- Bear Mountain Blvd Valid Days 350 353 292

4 th High 0.107 0.085 0.101 0.097 Bakersfield

- 5558 California Ave Valid Da ys 348 361 298

4 th High 0.091 0.08 0.094 0.088 Bakersfield

- Golden State Hwy Valid Days 362 358 209

4 th High 0.108 0.093 0.107 0.102 Edison Valid Days 361 361 301

4 th High 0.09 0.086 0.084 0.086 Maricopa

- Stanislaus Street Valid Days 351 291 265

4 th High 0.100 0.090 0.104 0.098 Oildale

- 3311 Manor Street Valid Days 354 357 303

4 th High 0.093 0.083 0.093 0.089 Kern

Shafter

- Walker Street Valid Days 361 353 303

4 th High 0.086 0.080 0 .083 Kings Hanford

- S Irwin Street Valid Days 339 297

4 th High 0.081 0.077 0.091 0.083 Madera Madera

- Pump Yard Valid Days 363 360 250

4 th High 0.086 0.087 0.105 0.092 Merced Merced

- S Coffee Avenue Valid Days 167 363 256

4 th High 0.083 0.075 0.077 0.078 San Joaquin Valley

San Joaquin Stockton

- Hazelton S treet Valid Days 362 361 267

## 7 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.093 0.079 0. 090 0.087 San Joaquin (continued) Tracy

- Airport Valid Days 355 354 269

4 th High 0.090 0.076 0.090 0.085 Modesto

- 14th Street Valid Days 358 362 268

4 th High 0.092 0.075 0.106 0.091 Stanislaus

Turlock

- S Minaret Street Valid Days 363 361 265

4 th High 0.104 0.099 0.112 0.105 Sequoia & Kings Canyon NP Valid Days 300 238 232

4 th High 0.097 0.091 0.101 0.096 Sequoia NP

- Lower Kaweah Valid Days 348 360 325

4 th High 0.092 0.086 0.105 0.094 San Joaquin Valley (continued)

Tulare

Visalia

- N Church Street Valid Days 361 361 301

4 th High 0.071 0.066 0.069 0.068 Atascadero

- Lewis Avenue Valid Days 356 352 330

4 th High 0.086 0.080 0.088 0.084 Carrizo Plains School

- Carrizo Valid Days 340 349 322

4 th High 0.053 0.053 0.058 0.054 Morro Bay Val id Days 351 343 320

4 th High 0.055 0.056 0.066 0.059 Nipomo

- Regional Park Valid Days 345 351 325

4 th High 0.072 0.068 0.064 0.068 Paso Robles

- Santa Fe Avenue Valid Days 360 363 190

4 th High 0.084 0.092 0.088 Red Hills Valid Days 3 62 330

4 th High 0.055 0.057 0.060 0.057 San Luis Obispo

San Luis Obispo

- S Higuera St Valid Days 356 356 242

4 th High 0.058 0.066 0.072 0.065 Carpinteria

- Gobernador Road Valid Days 349 354 272

4 th High 0.056 0.057 0.066 0.0 59 El Capitan Beach Valid Days 364 364 299

4 th High 0.055 0.055 0.058 0.056 Gaviota

- GTC Site B Valid Days 360 362 241

4 th High 0.064 0.057 0.062 0.061 Goleta

- Fairview Valid Days 364 358 301

4 th High 0.07 0.078 0.070 0.072 Las Flores Canyon #1 Va lid Days 363 360 330

4 th High 0.062 0.066 0.067 0.065 Lompoc

- HSandP Valid Days 363 358 301

4 th High 0.051 0.056 0.062 0.056 Lompoc

- S H Street Valid Days 362 356 302

4 th High 0.075 0.077 0.068 0.073 Paradise Road

- Los Padres NF Valid Days 363 355 301

4 th High 0.056 0.063 0.062 0.060 South Central

Coast

Santa Barbara

Santa Barbara

- E Canon

Perdido Valid Days 357 359 240

## 8 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.048 0.048 0.056 0.050 Santa Maria

- 906 S Broadway Valid Days 349 354 217

4 th High 0.064 0.063 0.067 0.064 Santa Ynez

-

Airport Road Valid Days 364 363 301

4 th High 0.059 0.069 0.065 0.064 Santa Barbara (cont inued)

Vandenberg AFB

- STS Power Valid Da ys 356 358 331

4 th High 0.059 0.061 0.065 0.061 El Rio

- Rio Mesa School #2 Valid Days 364 351 297

4 th High 0.094 0.076 0.081 0.083 Ojai

- Ojai Avenue Valid Days 363 361 301

4 th High 0.085 0.076 0.081 0.080 Piru

- 3301 Pacific Avenue Valid Days 359 358 304

4 th High 0.089 0.086 0.090 0.088 Simi Valley

- Cochran Street Valid Days 360 357 295

4 th High 0.076 0.074 0.077 0.075 Thousand Oaks

- Moorpark

Road Valid Days 364 358 301

4 th High 0.062 0.065 0.067 0.064 Ventura

Ventura

- Emma Wood State

Bch Valid Days 362 350 294 South Central Coast (continued)

Channel Islands NO MONITORS

4 th High 0.091 0.096 0.101 0.096 Azusa Valid Days 357 355 236

4 th High 0.098 0.088 0.092 0.092 Burbank

- W Palm Avenue Valid Days 358 356 235

4 th High 0.106 0.105 0.112 0.107 Glendora

- Laurel Valid Days 354 352 241

4 th High 0.095 0.063 0.079 Lebec

- Peace Valley Road Valid Days 321 82

4 th High 0.075 0.072 0.073 0.073 Los Angeles

- North Main Street Valid Days 355 337 224

4 th High 0.062 0.067 0.065 0.064 Lo s Angeles

- Westchester

Pkwy Valid Days 358 355 221

4 th High 0.064 0.057 0.055 0.058 Lynwood Valid Days 357 357 235

4 th High 0.057 0.057 0.064 0.059 North Long Beach Valid Days 354 350 236

4 th High 0.096 0.090 0.091 0.092 Pasadena

- S W ilson Avenue Valid Days 360 357 232

4 th High 0.078 0.079 0.077 0.078 Pico Rivera

- 4144 San Gabriel Valid Days 222 352 233

4 th High 0.108 0.103 0.100 0.103 Pomona Valid Days 354 352 238

4 th High 0.104 0.093 0.095 0.097 South Coast Los Angeles

Reseda Valid Days 355 339 242

## 9 Year

Basin Name County Name Site Name Statistic 2006 2007 2008* 2008* Design

Value

4 th High 0.112 0.102 0.103 0.105 Santa Clarita Valid Da ys 357 351 235

4 th High 0.068 0.067 0.075 0.070 Los Angeles (continued) West Los Angeles

- VA Hospital Valid Days 360 345 236

4 th High 0.071 0.074 0.076 0.073 Anaheim

- Pampas Lane Valid Days 361 357 239

4 th High 0.061 0.065 0.073 0.066 Costa Mesa

- Mesa Verde Drive Valid Days 362 341 236

4 th High 0.09 0.082 0.078 0.083 La Habra Valid Days 349 355 238

4 th High 0.09 0.081 0.092 0.087 Orange

Mission Viejo

- 26081 Via Pera Valid Days 353 358 239

4 th High 0.105 0.095 0.108 0. 102 Banning Airport Valid Days 353 359 237

4 th High 0.102 0.097 0.108 0.102 Lake Elsinore

- W Flint Street Valid Days 353 352 239

4 th High 0.114 0.103 0.106 0.107 Perris Valid Days 348 362 243

4 th High 0.112 0.099 0.111 0.107 Riverside

Riverside

- Rubidoux V alid Days 358 356 236

4 th High 0.111 0.126 0.120 0.119 Crestline Valid Days 363 365 234

4 th High 0.114 0.113 0.110 0.112 Fontana

- Arrow Highway Valid Days 351 346 234

4 th High 0.125 0.112 0.112 0.116 Redlands

- Dearborn V alid Days 364 362 244

4 th High 0.119 0.117 0.112 0.116 San Bernardino

- 4th Street Valid Days 356 352 236

4 th High 0.112 0.112 0.108 0.110 South Coast (continued)

San Bernardino

Upland Valid Days 360 354 236



### * 2008 data are preliminary and may not be complete. Therefore, the 20 08 Design Value should be
considered preliminary.