MEMORANDUM

Subject:  Tribal Consultation on Navajo Generating Station

From:  Colleen McKaughan, Associate Director, Air Division, USEPA Region 9  

To:  Docket EPA‐R09‐OAR‐2013‐0009

Date:  Consultation Occurred on April 29, 2013

USEPA, Region 9, invited all Arizona Tribes to meet with Janet McCabe, Principal

Deputy Assistant Administrator for the Office of Air and Radiation, and Colleen

McKaughan, Associate Director, Air Division Region 9, for the purpose of

consultation on EPA’s proposed BART determination for NGS. EPA was joined by

Letty Belin, Counselor to the DOI Deputy Secretary, and Kevin Black and Sandra

ETO of Bureau of Reclamation.

We met individually with Robert Palmquist of Strickland and Strickland,

representing Ak‐Chin leadership, who were unable to make the consultation. We

went over our presentation (attached) on the NGS BART proposal and responded

to questions. We offered to meet with the Ak‐Chin leadership at a later date.

We also met individually with Governor Mendoza and Lieutenant Governor Lewis

of the Gila River Indian Community, several members of the Tribal Council, and

multiple attorneys representing GRIC. (Sign In Sheet attached) The Tribal Leaders

stated their position and EPA responded to questions.

Lastly, we had group consultation open to all tribes in Arizona. The Tribes that

participated included the Gila River Indian Community, the Navajo Nation, the

Tohono O’odham Nation, and ITCA. (Sign In Sheet attached). We went over our

presentation on the NGS BART proposal and answered questions.

Further consultation during the public comment period was offered by EPA.
Region 9, Air Permits Office

Overview of EPA Proposed 

Rulemaking for

Navajo Generating Station

1

Janet McCabe

Deputy Assistant Administrator 

US Environmental Protection Agency, Office of Air and Radiation 

Meeting at the InterTribal Council of Arizona

April 29, 2013
Region 9, Air Permits Office

2
Region 9, Air Permits Office

Overview

• Notice of Proposed Rulemaking was published 

February 5

• Three parts: 

– BART: an emission limit for oxides of nitrogen (NOx) 

achievable with installation of selective catalytic 

reduction (SCR) in 5 years;

– Alternative to BART: framework to give NGS credit for 

early NOx reductions and provide NGS with more 

flexibility on the timing of compliance;

– Discussion of additional alternatives

3
Region 9, Air Permits Office

History of NGS

• Located on Navajo Nation and burns coal that is 

mined on Navajo Nation and Hopi Tribe

• U.S. Bureau of Reclamation owns 24.3% of NGS for 

the benefit of the Central Arizona Project

• NGS plays important roles in Arizona:

– Employment 

– Source of revenue to Navajo Nation and Hopi Tribe 

– Source of electricity 

– Electricity also used to pump CAP water and fulfill terms 

of several water settlement agreements with tribes 

located in Arizona

4
Region 9, Air Permits Office

Why Are We Evaluating NGS?

5

• Congress required EPA to improve visibility at 

National Parks and Wilderness Areas (Class I areas) 

– Regional Haze Program

• Large, old sources of air pollution that affect visibility 

in Class I areas must be evaluated to determine if 

new air pollution controls should be required (Best 

Available Retrofit Technology – BART)

• NGS affects visibility at 11 Class I areas, including 

Grand Canyon and Canyonlands and is subject to the 

BART requirement of the Regional Haze Program
Region 9, Air Permits Office

• Air pollutants (for example, gases like NOx that 

form particulate matter) cause regional haze

• By reducing emissions of air pollutants that cause 

haze, we can improve visibility 

• The same pollutants that impair visibility are a 

concern for human health, therefore reducing 

haze also improves air quality

• EPA or State Agencies evaluate whether new 

controls should be required for all facilities that 

are subject to BART requirement

How Do We Improve Visibility?

6
Region 9, Air Permits Office

• BART is determined based on a 5-factor analysis

– Factor 1 – How much would controls cost the facility?

– Factor 2 – Are there energy, economic, or other 

environmental impacts of the control?

– Factor 3 – What are the existing controls at the facility?

– Factor 4 – What is the remaining useful life of the 

facility?

– Factor 5 – How will visibility improve by adding 

controls?

How is BART determined?

7
Region 9, Air Permits Office

Brief Overview of 5-Factor Analysis

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LNB/SOFA SNCR + LNB/SOFA SCR + LNB/SOFA

Factor 1

Emission Limit 0.24 lb/MMBtu 0.18 lb/MMBtu 0.055 lb/MMBtu

Emission Reductions 10,865 tpy 16,608 tpy 28,573 tpy

Total Capital Costs $45 million $84 million $541 million

Average Cost Effectiveness $486/ton $1,745/ton $2,240/ton

2

Electricity Rate for SRP 

Customers in 2018 9.26 cents/kWh 9.28 cents/kWh 9.32 cents/kWh

Energy-only Water Rate for CAP 

Customers $58/acre-foot $61/acre-foot $66/acre-foot

3 Existing Controls LNB/SOFA were installed early and voluntarily in 2009-2011

4 Remaining Useful Life Amortization Period of 20 years; Lease extended to 2044

5

Largest Single Class I area 

Visibility Improvement 2.1 deciviews 3.1 deciviews 5.4 deciviews

Cumulative Visibility Improvement 16 deciviews 22 deciviews 35 deciviews
Region 9, Air Permits Office

• Based on our 5-factor analysis, EPA determined 

that installation of SCR + LNB/SOFA at NGS to 

reduce NOx emissions:

– is cost-effective 

– would not create a competitive disadvantage for NGS 

– would result in a perceptible improvement in visibility at 

the Class I areas affected by NGS

Why Did We Propose New Controls?

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Region 9, Air Permits Office

• Given the importance of NGS to tribes and its location on 

tribal land, it is appropriate to provide additional flexibility

• Compliance timeframes for alternatives to BART under the 

Regional Haze Rule that apply on state land do not apply 

on tribal land

• Under the Tribal Authority Rule, EPA determines if and 

when a FIP is necessary and appropriate, including the 

timeline for complying with those requirements

Why is EPA Proposing an Alternative?

10
Region 9, Air Permits Office

• The Regional Haze Rule (RHR) requires either BART or an 

alternative measure that will achieve greater reasonable 

progress than BART (Better than BART)

• EPA is proposing to give NGS credit for early and voluntary NOx

reductions in order to extend the compliance date to 2023 for 

meeting BART limits

• This alternative is Better than BART

• EPA included a framework for stakeholders to consider dates 

beyond 2023 by implementing additional emission reductions to 

meet the Better than BART threshold

Framework for Considering Alternatives

11
Region 9, Air Permits Office

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

500,000

550,000

If LNB and SCR 

Installed Concurrently 

by 2018

BART by 2018 with 

LNB as Installed in 

2009-2011

LNB Credit Alt 1 (21/22/23) Alt 2 (23/24/25) Alt 3 (24/25/26)

Total NOx Emissions over 2009 - 2044 

Alternative Compliance Year Scenarios

Better than BART Calculations and Comparison of Alternative 

Compliance Dates

Better than BART Threshold

Adjusted Emissions Accounting for LNB Credit

Adjusted Emissions Accounting for LNB Credit

Adjusted Emissions Accounting for LNB Credit

Emission Reduction Bridge 

LNB Credit LNB Credit LNB Credit LNB Credit

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Region 9, Air Permits Office

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• EPA has extended the comment period to August 5, 2013 

based on requests from Navajo Nation, GRIC, SRP, and 

CAWCD

• Consultation will be on-going during the public comment period

• EPA will hold public hearings towards the end of the comment 

period

• EPA anticipates stakeholders will suggest other Better than 

BART alternatives for more time to comply with the BART 

limits

• EPA will evaluate suggested alternatives and may put forth a 

supplemental proposal

What Happens Next?
Region 9, Air Permits Office

14

• EPA, DOI, and DOE have committed to work together to 

support stakeholder interests in NGS 

– Create a long-term EPA-DOI-DOE Working Group 

– Work with stakeholders, including the owners of NGS, tribes and other 

CAP water users, and environmental and community groups, to develop 

a roadmap to achieve long-term goals related to clean energy, 

sustainable water supplies, and sustainable economic development

– Complete the Phase 2 report on clean energy options for NGS

– Support shorter term investments that align with long term clean energy 

goals

• The Working Group is a separate process from BART

Joint Federal Agency Workgroup
Region 9, Air Permits Office

15

• EPA will review and consider all comments before 

making a final decision

• We will respond to all comments in writing and 

incorporate any changes to the proposal as a result 

of comments in our final decision

• Documents will also be posted online and in our 

docket for this rulemaking

What Happens After the Comment Period?
Region 9, Air Permits Office

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For Further Information

Name Role Phone Email

Colleen 

McKaughan

Associate Director, 

Air Division

520.498.0118 McKaughan.Colleen@epa.gov

Ann Lyons Office of Regional 

Counsel

415.972.3883 Lyons.Ann@epa.gov

Anita Lee Staff Lead, Air 

Division

415.972.3958 Lee.Anita@epa.gov