### STATE OF CALIFORNIA

S TAFF REPORT

ANALYSIS OF THE

SAN DIEGO COUNTY AIR POLLUTION CONTROL DISTRICT

2012 REDESIGNATION REQUEST AND MAINTENANCE PLAN

FOR THE 1997 NATIONAL OZONE STANDARD

Date of Release: November 15 , 2012

Scheduled for Consideration: December 6, 2012

This report has been reviewed by the staff of the California Air Resources Board and

approved for publication. Approval does not signify that the contents necessarily

reflect the views and policies of the Air Resour ces Board, nor does mention of trade

names or commercial products constitute endorsement or recommendation for use.2 

## TABLE OF CONTENTS

I. EXEC UTIV E SUMMARY.

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

II. REDESIGNATION REQUIREMENTS

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

III. EVALUATION OF THE SA N DIEGO OZONE PLAN.................

. .. 4

A. Sa n Diego County Attains the Ozone Standard ............................4

B. The State Has Met Applicable Act Requirements ..........................5

C. Improvement in Sa n Diego Ozone Air Quality is Due to

Permanent and Enforceable Reductions in Emissions

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

D. Maintenance Plan

1. Attainment Emission Inventory

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

2. Maintenance Demonstration

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

3. Ozone Monitoring Network

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

4

. Verification of Continued Attainment

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

5. Conti ngency Provisions

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

6. Transportation Conformity Budgets

.................................... . . 8



### IV. STAFF RECOMMENDATION..............................................

. . . 83



### I. EXECUTIVE SUMMARY

O n June 13, 2012 , the U

. S

. Environmental Protection Agency ( U.S. EPA ) classified

San Diego as a “Moderate” nonattainment area for the 1997 8

- Hour Ozone National

Ambient Air Quality Standard (standard), requiring a State Implementation Plan

( SIP ) addressing Moderate area control requirements to be submitted to U.S. EPA

by June 13, 2013

. The classification, which was made in response to a court order,

was based on 2001 to 2003 air quality data. However, more recent data show that

San Diego attained the standard in 2011 . The San Diego Air Pollution Control

District’s (District) 2012 Redesignation Request and Maintenance Plan

(Maintenance Plan) demonstrates that the region’s air quality now meets the federal

standard, and that it will contin ue to do so through at least 2025. If approved by

U.S. EPA , the Maintenance Plan will fulfill all applicable SIP requirements for the

1997 8

- Hour Ozone Standard.

T he District ’s G overning B oard is scheduled to consider adopt ion of the

Maintenance Plan on December 5, 2012

. ARB staff has reviewed the Draft

Maintenance Plan released on November 2, 2012 and finds that the Maintenance

Plan meets all applicable federal Clean Air Act ( CAA ) requirements for redesignation

requests and maintenance plans

. Staff recommends that the Board approve the

Maintenance Plan contingent on ARB staff’s determination that the Maintenance

Plan approved by the District Board does not differ significantly from that reviewed

by ARB staff, and that the Board direct staff to subm it the Maintenance Plan to

U.S. EPA as a proposed revision to California’s SIP.



### II. REDESIGNATION REQUIREMENTS

ARB staff reviewed the Maintenance Plan within the context of the CAA, which

identifies the following requirements that a nonattainment a rea must meet in order to

be redesignated to attainment:

 Attainment of th e standard has been demonstrated ;

 The State has met all applicable CAA requirements for ozone in the

nonattainment area;

 The area has an approved SIP;

 The area’s improvement in air quality is d ue to permanent and enforceable

ozone emission reductions; and

 The area has a U.S. EPA

- approved maintenance plan.

The CAA also sets the general framework for maintenance plans

. Each ozone

maintenance plan must provide for continued maint enance of the ozone s tandard for

10 years after redesignation

, and must i nclude the following components:

 A detailed emission s inventory;

 A m aintenance demonstration;

 A c ommitment to continue operation of the monitoring network ;4

 A c ommitment to verif y con tinued attainment; and

 A c ontingency plan to promptly correct any violation of the stan dard that

occurs after redesignation

.



### III. EVALUATION OF THE SAN DIEGO PLAN

Based on review of the Maintenance Plan and the District’s supporting technical

analysis, ARB staff co ncurs that the Maintenance Plan meets the CAA requirements.

The following sections describe the major elements of the Maintenance Plan.

A. Redesignation Request: San Diego Attains the 1997 8

- hour Ozone Standard

The San Diego District operates an ext ensive ozone monitoring network that

continuously monitor s ambient ozone levels at numerous sites throughout San

Diego County in complian ce with federal requirements

. The data generated at these

monitors are used to define the natu re and severity of ozone pollution in San Diego

County, to identify ozone pollution trends, and to determine compliance with ozone

air quality standard s

.

Data from the San Diego monitoring network show that the area a ttained the 1997

8

- hour ozone standar d, which is 0.08 parts per million ( ppm ) , in 2011

. Figure 1

m ap s the ozone monitors operat ing in the nonattainment area during the 2009

through 2011 attainment peri od

. Table 1 shows the fourth

- highest daily maximum

8

- hour average ozone concentratio n recorded at each monitoring site in each of the

past three consecutive years

. U.S. EPA regulations specify that the three

- year

average of the fourth

- highest daily concentrations recorded at each site must be

used to determine whether a region attains the standard. The highest resulting

averaged value is known as the ozone "design value" for the region ; t he 1997 8

- hour

ozone standard is attained when a region's design value is less than or equal to

0. 084 ppm. Table 1 shows that S an Di ego County's ozone design value is 0.082

ppm

. San Diego’s design value is established at the Alpine monitoring station

, which has historically recorded the highest ozon e concentrations in the region. As

shown in Table 1

, the 1997 8

- hour ozone standard has been attained thr oughout the

San Diego County Planning Area

.

Data from the 2012 ozone season ha ve not yet be en fully reviewed. P reliminary

data indicate that the area continues to be in attainment of the 1997 ozone standard

to date

.5 Figure 1. Ozone Monitoring Stations in San Diego County

Table 1. San Diego County Ozone Data : Annual Fourth

- Highest Daily

Maximum Concentrations (ppm)

Monitor Site 2009 2010 2011 3

- Year

Average

Alpine 0.085 0.081 0.082 0.082

Camp Pendleton 0.071 0.064 0.067 0.067

Chula Vista 0.067 0.068 0.055 0.063

Del Mar 0.067 0.063 0.064 0.064

Downtown 0.060 0.058 0.060 0.059

El Cajon 0.071 0.073 0.070 0.071

Escondido 0.074 0.075 0.068 0.072

Kearny Mesa 0.069 0.070 0.069 0.069

Otay Mesa 0.061 0.056 0.059 0.058

B. The State Has Met Applicable Clean Air Act Requirements

ARB and the District have met all of the CAA requirements applicable for a M oderate

ozone nonattainment area to be considered for redesignation. U.S. EPA ful ly

approved San Diego’s 1

- hour O zone Maintenance Plan on July 28, 2003; this p lan

remains the applicable ozone SIP for San Diego until U.S. EPA approves a

subsequent ozone SIP submittal (San Diego’s 2012 Redesignation Request and

Maintenance Plan ). No SIP provisions are currently disapp roved, conditionally

approved, or partially approved.6

C. Improvement in San Diego’s Ozone Air Quality is Due to Permanent and

Enforceable Reductions in Emissions

The Maintenance Plan projects that o zone precursor emissions will continue to

decline through the maintenance period despite projected increases in population,

motor vehicle use, meteorological fluctuations, and economic recovery. The benefit s

of the adopted rules and regulations are projected to continue through the

ma intenance period as older vehicles, engines, and equipment are replaced with

newer units subject to more stringent emission control requirements. The

Maintenance Plan also identifies the adopted State and l ocal regulations that,

together with federal cont rols, brought the area into attainment of the 1997 ozone

standard

.

D. Maintenance Plan

The Maintenance Plan also includes the components need ed to demonstrate that

the area will remain in attainment of the 1997 ozone standard : an attainment

emission inventory that is projected to decline through 2025 ; a commitment to

continue operation of the monitoring network ; a commitment for verification of

continued attainment; and a contingency plan.

1. Attainment Emission Inventory

Ozone is formed in the air by reactions of ozone precursor emissions, volatile

organic compounds (VOC) and oxides of nitrogen (NOx), in the presence of sunlight

and heat. Because San Diego attained the 8

- hour ozone standard in 2011, total

daily VOC and NOx emissions in 201 1 represent the a ttainment i nventory (see

Table 2) . The attainment i nventory shows average t otal ozone precursor emissions

of 142.6 tons per day (tpd) VOCs and 137.5 t pd NOx

.

Table 2. San Diego County 2011 Ozone Attainment Inventory

Summer Planning Inventory, tpd

Precursor Emissions

Volatile organic compounds (VOC) 142.6

Nitrogen oxides (NOx) 137.5

2. Maintenance Demonstration

In addition to the 2011 adjusted baseline inventory of ozone precursor emissions,

the Maintenance Plan provides emission projections through the year 2025. These

projections incorporate the effects of projected growth in population, vehicle travel,

and economic activity, as well as the effects of adopted regulations . As shown in

Table 3

, emissions of ozone precursors will continue to decline through 2025.

Because potential changes in military activities do not follow socioeconomic factors,

the District included a projection of future mobile source emissions from potential7

additional military activi ty

, obtained from the Department of the Navy, in its inventory

projections

. The projected inventory also includes banked emission reduction

credits as a line item to demonstrate that the use of banked emissions credits will

not interfere with maintenance

.

Table 3. Emissions Trends

Emissions Source Category 2002 2011 2015 2020 2025

VOCs

Stationary Sources 28.4 31.1 33.1 35.8 36.8

Areawide Sources 42.2 35.9 35.3 36.7 37.5

On

- Road Motor Vehicles 63.4 35.3 26.4 20.5 18.3

Non

- Road Mobile Sources 49.1 40.3 37.1 35.4 36.1

Banked Emission Credits 0.9 0.9 0.9

Potential Future Military Activity 1.0 1.0 1.0

Total VOCs 183.1 142.6 133.9 130.3 130.6

NOx

Stationary Sources 8.2 6.3 5.6 5.5 5.6

Areawide Sources 1.9 1.7 1.8 1.9 2.0

On

- Road Motor Vehicles 119.9 70.9 52.5 35.9 27.6

Non

- Road Mobile Sources 68.0 58.6 54.9 50.4 47.5

Banked Emission Credits 0.7 0.7 0.7

Potential Future Military Activity 4.4 4.4 4.4

Total NOx 198.1 137.5 119.9 98.9 87.8

The declining inventory indicates that San Diego will maintain attainment of the 1997

ozone standard due to ARB, District, and federal c ontrol measures that are already

in place.

3. Ozone Monitoring Network

San Diego County’s nine

- station ozone monitoring network substantially exceeds

U.S. EPA requirements, which call for two ozone monitoring sites in an area of this

size.

4. Verification of Continued Attainment

In the Maintenance Plan, the District commits to continue ozone monitoring to verify

continued attainment of the 1997 ozone standard. The Maintenance Plan also

includes a commitment to continue air monitoring data collection, verification, and

submittal in compliance with federal guidelines.

5. Contingency Plan

The CAA require s th at a maintenance plan include contingency provisions for

prompt correction of any violation of an air quality s tandard that might occur after the

area has been redesignated to attainment for that standard

. U.S. EPA’s8

requirements speci f y that the area must have a plan e nsure s that contingency

measures will be adopted if the area goes out of attainment

.

The San Diego Maintenance Plan cites ARB mobile source control regulations that

were not included in the emission projections as contingency measure s that will

provide signific ant continuing emissions reductions through the maintenance period

. The Maintenance Plan also includes a District commit ment to adop t and implement

additional emission control measures needed to ensure maintenance if a violation of

the 1997 ozone standard is recorded

. ARB staff concurs that the Maintenance Plan

meets CAA contingency plan requirements.

6. Transportation Conformity Budgets

The CAA ’s transportation conformity requirements are designed to ensure that

transportation planning is consistent wit h air quality goals. Conformity is determined

by comparing emissions from proposed projects and transportation system plans to

the transportation conformity budgets established in the SIP

.

The Maintenance P lan includes the transportation conformity budgets shown in

Table 5. The San Diego Association of Governments and District staffs agreed to

use the projected on

- road motor vehicle inventories for 2020 and 2025, rounded up

to the nearest ton and i ncreased by two tons , to develop the transportation

conformity budgets. The se budgets provide room for economic recovery that

exceeds current projections, but are still substantially lower than the 2011 on

- road

emissions levels that resulted in attainment of the 1997 ozone standard. If approved

by the Di strict Board in December 2012 , these budgets will meet CAA requirements.

Table 5. Emissions Budgets for Transportation Conformity

Ozone Precursor 2020 (Interim Year) 2025 (Horizon) and

Subsequent Years

VOC 23 tpd 21 tpd

NOx 38 tpd 30 tpd



### IV. STAFF RECOMMENDATION

ARB staff has reviewed the Maintenance Plan for San Diego and consulted with

District staff during this review. ARB staff finds that the Maintenance Plan meets all

applicable CAA requirements. ARB staff believes that implementation of this

Maintenance Plan will continue to maintain ozone levels below the 1997 8

- hour

ozone National Ambient Air Quality Standard in the San Diego County Planning

Area

. Therefore, staff recommend s that the Board adop t the San Diego County

2012 Redesignation Request and Maintenance Plan as a revision to the California

SIP for submittal to U.S. EPA. Staff further recommends that the Board approve the

District’s request that the San Diego County Planning Area be redesignated from

nonattainment to attainment for the national ozone standard.