How Tribes Use ModelsPart 1

Navajo Nation Environmental Protection Agency

Tribes

Air Quality Planning

New Source Review

Environmental Assessments

ComplianceTracking

Air Quality

Planning

FIP/SIP/TIP

CAARulemaking

NAAQS

Regional Haze

New Source Review

Emission LimitsOperating Condition

Control Technology

(BACT, RACT, MACT)

Tribal Minor Source(TNSR) Prevention of

Significant Deterioration

(“PSD”)

Non-Attainment

Minor Source(“NA NSR”)

Lease Renewal Major SourceSiting New Source

Class 1 AreasAir Shed Protection

Environmental Assessments Emission Inventory

Existing Sources Impacts

Validation of Air Quality MonitorsSiting Air Monitors

Compliance Tracking

Navajo Nation Case Study

• Environmental Impact Statement– Four Corners Power Plant & Navajo Mine– Navajo GS & Peabody Mine

• PSD Permits– Desert Rock , Navajo GS, Four Corners

• Best Available Retrofit Technology (“BART”)– NGS, FCPP

• Tribal Minor New Source Review

Four Corners Power Plant and Navajo Mine Energy Project

• Power Plant Lease Amendment• Energy Transmission Lines• Coal Mine Area

Air Quality Modeling • Class II / Criteria Pollutant Modeling– Impacts from FCPP and Navajo Mine– Met data/ Ambient Background– Nearby Sources/Fenceline/Boundary

• Class II Plume Visibility Modeling• Class 1 Modeling ( “BART”) and Acid

Deposition• EIS Section 7/ESA• Ozone Modeling • AERMOD, PLUVUE II, CALPUFF, CAMx