GIS Applications for Air Quality Management Robert Wu 吳震球 South Coast Air Quality Management District SCCAEPAApril 26, 2008

Geographic Information System A Definition of GIS GIS is a system of computer software, hardware, data, and personnel to help manipulate, analyze and present information that is tied to a spatial location

GIS Applications for Air Quality Management Providing Air Quality Information Health Risk Assessment Tool Compliance/Enforcement Tool Environmental Impact Analysis Planning/Analytical Tool

GIS Applications for Air Quality Management (cont’d) Exposure Studies Identify Hot Spot Areas Rule Development Identification of Sources Proximity Analysis

South Coast Air Quality Management District

South Coast Air Quality Management District Source/Receptor Areas

South Coast Air Quality Management District Air Monitoring Stations

Public Information on Air Quality (Ozone Levels)

Air Dispersion Modeling

Cancer Risk Isopleth

Proximity of Regulated Facilities to a Proposed School Site

Impact of Emission of Toxic Air Contaminants on a Community

Regulated Sources of Emissions- All Types

Specific Type of Regulated Industries

Chrome Plating Facilities- Toxic Air Contaminant Sources

Proximity of Schools to Chrome Plating Facilities

Emission Inventory Gridded Emissions

Proximity Analysis- Buffering

AERMOD Regulatory Status and Applicability AERMOD is now an EPA Guideline Model, replacing ISCST3 Published in Federal Register 9 Nov 2005 Became Effective 9 Dec 2005 First major short-range model promulgation in 25 years Applicable for distances up to 50 km 1-Year grace period for ISCST3

Implications for Departure of ISCST3 This is a big deal - ISCST3 used around the world In California, ISCST3 can still be used for State-only programs, BUT –ARB is moving the HARP model and air toxic program to AERMOD –Future ISCST3 modeling will be subject to criticism of not reflecting “best science” –Most District rules require permit modeling to follow EPA’s Guideline on Air Quality Models

AERMOD Overcomes Many ISCST3 Deficiencies Meteorology treatment Dispersion treatment Building wake treatment Terrain treatment

AERMOD Modeling System Structure AERMAP (Terrain) AERMAP (Terrain) AERMET (Meteorology) AERSURFACE (Boundary Layer) AERMOD (Dispersion) AERSCREEN (Screening) Development In Progress

ISCST3: –Elevation of each receptor point input –Predictions are very conservative in complex terrain AERMOD: –Controlling hill elevation and point elevation at each receptor are input –Predictions are nearly unbiased in complex terrain Comparison of Dispersion Model Features: Complex Terrain Modeling

Overall Summary of Model Formulation AERMOD is based on a newer understanding of atmospheric turbulence and dispersion AERMOD solves many identified problems with ISCST3 The issue of over-predictions in complex terrain is eliminated

Implementation of AERMOD in Southern California Air Resources Board HARP incorporates ISCST3 as an internal module ARB will upgrade HARP to AERMOD –Definitive plans not yet made –Implementation highly unlikely by Dec 2006 –Critical decision: internal module vs external file ARB staff have begun to run AERMOD No current plans to hold AERMOD training courses for District staff Not Discussed: Where is the funding coming from? 2/1/06

Reasons to Begin the Switch to AERMOD ISCST3 will be allowed only until 9 Dec 2006 ARB is implementing AERMOD in HARP Restrictive ISCST3 modeling results may be relaxed with AERMOD Facilities with complex terrain and building downwash issues expect the largest benefit AERMOD is a complex model with a long learning curve

Expect to Buy a Faster Computer Real World ENSR Permit Modeling AERMOD Run 3.0 GHz Intel XEON Workstation 317 Sources: –72 point sources (60 w/ downwash) –236 volume sources –9 area sources 3,563 Receptors 1.13 Million Source-Receptor Pairs 215 source-receptors / min 87.6 hours elapsed run time

Difficulties Ahead with Implementation Meteorological data acquisition –Specific data requirements for AERMOD –EPA requiring 3-5 years of data –Quality upper air data critical Funding –Where will ARB get funding for HARP development? –Where will Districts get training budgets? –Where will Districts get funding to upgrade their meteorological monitoring networks if needed?

Impact Analysis of Emissions Gridded emission inventory Temporal emission analysis Show relationships between emissions and health effects data Siting of new schools or facilities Impact on sensitive receptors (schools, day- care centers, hospitals, etc )

AB 2588 Emission Inventory Prioritization Risk Assessment Public Notice Risk Reduction California program under the Air Toxics Hot Spots Information and Assessment Act of 1987, Health and Safety Code Section 44300

Hotspots Analysis and Reporting Program HARP Effective in 7/1/2005, required in Tier IV Emission Inventory - CEIDARS Dispersion Modeling – ISCST Mapping – GIS Analysis - HRA

Toxics Emission Inventory Assembly Bill 2588 SCAQMD MATES Project Community Health Air Pollution Information System (CHAPIS) California Emission Inventory Development and Reporting System (CEIDARS 2.5)

Rule 1401 New Source Review for Air Toxics Adopted in June 1, 1990 Initially specified limits for maximum individual cancer risk (MICR) and excess cancer cases for new, related, or modified sources which emit carcinogenic air contaminants Amended several times to include non- carcinogenic compounds and to update the list of toxic compounds and the corresponding risk values

Rule 1401 New Source Review for Air Toxics Risk-based Regulation 4-Tier Health Risk Assessment (HRA) –Tier I– Screening Emission Levels –Tier II– Screening Risk Assessment –Tier III– Screening Dispersion Modeling –Tier IV– Detailed Risk Assessment Standards –Cancer Risk > without T-BACT –Maximum Risks for each permit unit: Cancer Risk = Cancer Burden = 0.5 Hazard Index = 1.0

Rule 1401 New Source Review for Air Toxics