### ENCLOSURE 1



## State of California State of California

AIR RESOURCES BOARD AIR RESOURCES BOARD

January 2011 

### RECOMMENDED
AREA DESIGNATIONS
FOR THE 2010 FEDERAL
NITROGEN DIOXIDE
STANDARDS

Technical Support Document

California Environmental Protection Agency



# Air Resources Boardi TABLE OF CONTENTS

Page

BACKGROUND .........................................

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

NITROGEN DIOXIDE AIR QUALITY .......................

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

RECOMMENDED AREA DESIGNATIONS...................... ........................................... 2

NITROGEN DIOXIDE MONITORING NETWORK REQUIREMENTS .. ..................... 4

SUMMARY............................................

................................................... ................... 5ii LIST OF TABLES AND FIGURES

Page

FIGURE I: South Coast Maximum 1-Hour NO 2 Concentration
for the Federal Standard.......................... ............................................ 2

TABLE I: Recommended California Attainment Areas f or the Federal 1-Hour and Annual Average NO 2 Standard.......................................... 3

TABLE II: Recommended California Unclassifiable Ar eas for the Federal 1-Hour and Annual Average NO 2 Standard.......................................... 3

TABLE III: Required Near-Roadway Monitors in California for the Federal NO 2 Standard Core Based Statistical Areas with a Population of 500,000 or more.... 41

BACKGROUND

This technical report provides Air Resources Board (ARB) recommendations on designations for the revised federal nitrogen dioxi de (NO 2 ) standard based on air quality monitoring data for California.

On January 22, 2010, the United States Environmenta l Protection Agency (U.S. EPA)
established a new national 1-hour NO 2 standard of 100 parts per billion (ppb) and retained the annual average standard of 53 ppb. In addition, U.S. EPA added new near-roadway monitoring requirements. The final ru le was published in the Federal Register on February 9, 2010.

http://www.epa.gov/ttn/naaqs/standards/nox/fr/20100 209.pdf

Under the Clean Air Act all states, including Calif ornia, must develop recommendations for area designations and appropriate boundaries. These area designations specify the status of each area of the State with respect to co mpliance with the standards. These area designation recommendations are due to U.S. EP A by January 22, 2011. U.S. EPA then has one year to review these recommen dations and to issue final designations by January 22, 2012.

NITROGEN DIOXIDE AIR QUALITY

The first federal NO 2 standard was established in 1971, which was an ann ual average
NO 2 standard of 53 ppb. The federal NO 2 standard was not revised until 2010, when the new 1-hour standard of 100 ppb was added and th e annual standard was retained.
NO 2 is emitted into the atmosphere from combustion pro cesses which include boilers, furnaces, utilities, and mobile sources. U.S. EPA estimates that nationally mobile sources account for 58 percent of NO 2 emissions.

California has attained the annual average standard since 1998, with current annual average NO 2 concentrations ranging from 1 to 28 ppb. In the e arly 1980’s, 1-hour NO 2 concentrations in California were as high as 300 pp b, three times the level of the new 1-hour standard. Today, 1-hour NO 2 concentrations range from 6 to 85 ppb, well below
the level of the federal 1-hour NO 2 standard. The long-term trend in 1-hour NO 2 concentrations, shown in Figure 1, shows a decline of 60 percent at two urban sites that currently measure some of the highest NO 2 concentrations (Pomona and North Long Beach). Staff expects NO 2 concentrations to continue to decline as a result of new emission control programs that will be implemented over the next decade to meet
federal ozone and PM2.5 standards.2 FIGURE I

South Coast Maximum 1-Hour NO 2 Concentration

for the Federal Standard

South Coast 1 Hour NO 2 Concentrations

0 50 100 150 200 250 300

1982 1985 1988 1991 1994 1997 2000 2003 2006 20091 hour NO2(ppb)

North Long Beach Pomona Standard

RECOMMENDED AREA DESIGNATIONS

ARB staff evaluated the available ambient NO 2 data to determine appropriate area designations throughout the State. The recommendat ions in this report are based on
NO 2 air quality data collected between 2007 and 2009. The analysis was conducted for each monitoring site in the State for which data ar e available. Both annual average and
1-hour NO 2 concentrations were evaluated. The annual average is calculated by averaging all hourly NO 2 concentrations measured during a year. Compliance with the 1-hour standard is based on averaging the 98 th percentile hourly NO 2 concentration over a 3-year period. Generally, the 98 th percentile is the eighth highest 1-hour NO 2 concentration measured during a year. However, if data are incomplete, a higher value may be used, in accordance with established U.S. EP A criteria.

Based on ARB staff’s analysis, no areas in Californ ia have monitored violations of either the federal 1-hour or annual average NO 2 standards. Therefore, ARB staff is recommending that all areas with valid data be desi gnated attainment for the revised
NO 2 standards, and areas with limited or no NO 2 air quality data be designated unclassified. U.S. EPA has not yet issued guidance on determining the boundaries for
attainment or nonattainment areas. In the absence of U.S. EPA guidance, our
recommendations are based on a combination of distr ict and district/county boundaries in order to maximize air quality management objecti ves. The NO 2 federal design values
for areas recommended as attainment are listed in T able I, while areas recommended
as unclassified are listed in Table II.3 TABLE I

Recommended California Attainment Areas for the Federal 1-Hour and Annual Average NO 2 Standard

Designation Attainment Area 1-hour Design Value (ppb) Annual Average

Design Value (ppb) Bay Area AQMD 54 16 Butte County AQMD 38 8
Feather River AQMD 49 9 Imperial County APCD 72 14 Mendocino County AQMD 32 5 Mojave Desert AQMD 63 16 Monterey County – Monterey Bay Unified APCD 34 6 Santa Cruz County – Monterey Bay Unified APCD 22 2 Placer County APCD 53 10 Sacramento Metropolitan AQMD 56 13 San Diego County APCD 85 21 San Joaquin Valley Unified APCD 61 18 San Luis Obispo County APCD 42 7 Santa Barbara County APCD 35 10 Los Angeles County - South Coast AQMD portion 81 28 Orange County – South Coast AQMD 69 21 Riverside County – South Coast AQMD portion 63 20 San Bernardino County – South Coast AQMD portion 74 24 Ventura County APCD 45 11 Attainment

Yolo-Solano AQMD 36 7

TABLE II

Recommended California Unclassified Areas for the Federal 1-Hour and Annual Average NO 2 Standard

Designation Unclassified Area

Antelope Valley AQMD Amador County APCD Calaveras County APCD Colusa County APCD

Eastern Kern APCD El Dorado County AQMD Glenn County APCD

Great Basin Unified APCD Lake County AQMD Lassen County APCD Mariposa County APCD* Modoc County APCD San Benito County – Monterey Bay Unified APCD
North Coast Unified AQMD*
Northern Sierra AQMD* Northern Sonoma County APCD Shasta County AQMD Siskiyou County APCD Tehama County APCD Unclassified

Tuolumne County APCD

* These areas have incomplete data. Remaining areas have no data.4

NITROGEN DIOXIDE MONITORING NETWORK REQUIREMENTS

In addition to revising the NO 2 standard, U.S. EPA also established new monitoring requirements that are oriented towards assessing th e impact of emissions from mobile sources. The most significant change is the requir ement for a new monitoring network
to measure NO 2 concentrations near major roadways in urban areas with a population of 500,000 or more. Sixteen new near-roadway monit oring sites will be required in California. These monitors are required to be depl oyed by January 2013.

U.S. EPA is developing near-road monitoring guidanc e to address many technical issues related to deploying near-road monitors. In conjunction with the development of near-roadway guidance, U.S. EPA and the National As sociation of Clean Air Agencies are collaborating to conduct a near-road monitoring pilot study. The purpose of the pilot is primarily to allow U.S. EPA, state, and local a ir monitoring stakeholders to evaluate, improve, and document the near-road monitor siting process.

Table III shows where new near-roadway monitors wil l be required in California.

TABLE III Required Near-Roadway Monitors in California for th e Federal NO 2 Standard Core Based Statistical Areas (CBSA) with a Populati on of 500,000 or more

Core Based Statistical Areas County(ies) Population Number of
Monitors
Bakersfield Kern 800,458 1
Fresno Fresno 909,153 1 Los Angeles-Long Beach-Santa Ana Los Angeles, Orang e 12,872,808 2 Modesto Stanislaus 510,694 1
Oxnard-Thousand Oaks-Ventura Ventura 797,740 1
Riverside-San Berd-Ontario Riverside, San Bernardin o 4,115,871 2
Sacramento-Arden Arcade-Roseville Sacramento, Place r 2,109,832 2 San Diego-Carlsbad-San Marcos San Diego 3,001,072 2

San Francisco-Oakland-Fremont Alameda, Contra Costa, San Francisco, San Mateo, Marin 4,274,531 2

San Jose-Sunnyvale-Santa Clara Santa Clara 1,819,19 8 1 Stockton San Joaquin 672,388 1

There are also two additional monitoring requiremen ts. First, states are required to continue operating monitors to measure community-wi de exposures. There are 99 NO 2 monitors of this type in California, which far exce eds the minimum federal requirements. The second monitoring requirement will be implement ed by the U.S. EPA. Working with the states, EPA Regional Administrators will specif y at least 40 additional NO 2 monitors across the United States to help protect communitie s that are susceptible and
vulnerable to NO 2 -related health effects. The new monitoring data m ay result in a need to change area designations in the future. ARB wil l revise the area designation recommendations, as appropriate, once the new monit oring data becomes available.5

SUMMARY

ARB has used California’s air quality monitoring da ta to develop recommended area designations for U.S. EPA’s revised NO 2 air quality standard. Currently no counties in
California exceed the revised standard. All urban areas are recommended to be designated as attainment. Several rural areas are r ecommended to be unclassified at
this time since additional data is needed to meet U .S EPA requirements for designation as attainment. U.S. EPA is expected to issue final designations by January 22, 2012. These designations may later need revision when the results of the newly required near-road monitoring are available.