State Implementation Plan for 8-Hour Ozone in San Diego

Planning and Technical Support Division

May 24, 2007

San Diego

Overview

8-hour ozone standard and classification

Ozone air quality and emission trends SIP framework Attainment demonstration Control strategy Staff recommendations

Ozone Health Effects Inflammation and irritation of lung tissue Coughing, chest tightness, and

increased asthma Increases in hospital admissions and ER

visits Increases in premature mortality in

elderly people with chronic lung disease and circulatory system diseases

Compromises immune system

8-hour Ozone Standard U.S. EPA promulgated a new 8-hour

ozone standard—0.08 ppm established classification for

nonattainment areas outlined emission controls and

planning elements

San Diego’s Profile

San Diego’s Ozone Classification

“Basic” nonattainment area Refers to 8-hour nonattainment areas

that met the former 1-hour standard “Basic” areas must meet Subpart 1

requirements of the Clean Air Act less prescriptive than Subpart 2

Air Quality Trends Attained 1-hour ozone standard in 2001 Significant air quality improvement

Design value decreased 15% over last 10 years

Days over the standard decreased 54% over last 10 years

San Diego Federal 8-hr Ozone

Design Value (1990-2006)

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Year

Design Value (ppm) 8-hour ozone standard

2006 DV 0.088ppm

Federal 8-hr Ozone Exceedance Days (1990-2006)

0

20

40

60

80

100

120

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Year

Exceedance Days

14 days over the standard in 2006

Sources of Ozone Forming Emissions

Main sources of NOx: passenger vehicles, ships and commercial boats, and off-road equipment

Main sources of ROG: passenger vehicles, consumer products, architectural coatings, recreational boats, and lawn and garden equipment

San Diego Trends

0

100

200

300

400

500

600

700

800

900

1000

1990 1995 2000 2005 2010 2015 2020

VMT (x100,000) Population (x10,000) ROG NOx

SIP Framework

Emission Inventory Attainment Demonstration New Weight of Evidence guidelines Control strategies Transportation conformity emission

budgets

Attainment Demonstration

Photochemical modeling for “basic” areas

Design value of 84 ppb or less is considered attainment

Must show a full clean year (2008) before June 15, 2009 attainment deadline

Supplemental Weight of Evidence Now Required

Recognizes uncertainty inherent in air quality modeling

Uses measured air quality and meteorological data

If design value is between 82-87 ppb, supplemental analysis can be used to demonstrate attainment

San Diego’s Attainment Demonstration

District photochemical modeling predicts a 2008 design value of 86 ppb

ARB staff modeled additional episode Coincides with

direction of San Diego’s findings

San Diego’s Weight of Evidence Analysis

Unmonitored areas analysis Modeled ozone exposure reduction Air quality trend data

Includes 30, 20, and 10-year trends of design value reduction

Emission trends Meteorology of recent years Shortened ozone season

Transportation Conformity

Establish budgets for transportation conformity

Pollutant 2008 and Subsequent Years (tons per year)

ROG 53

NOx 98

Control Strategy

District controls meet former 1-hour “serious” requirements

Existing controls provide necessary reductions for 2009 attainment

State triennial update is due in late 2007 and will include an “all feasible measures” assessment

Staff Recommendations

Plan is technically sound and meets applicable requirements

Staff recommends adoption of 2007 San Diego 8-Hour SIP and submittal to U.S. EPA