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PETITION TO THE UNITED STATES 

DEPARTMENT OF THE INTERIOR

NATIONAL PARK SERVICE

PETITION ASKING THE DEPARTMENT OF THE INTERIOR FORMALLY TO CERTIFY

TO THE U.S. ENVIRONMENTAL PROTECTION AGENCY THAT VISIBILITY

IMPAIRMENT IN GRAND CANYON NATIONAL PARK IS REASONABLY

ATTRIBUTABLE TO NITROGEN OXIDES AND PARTICULATE MATTER EMISSIONS

FROM THE NAVAJO GENERATING STATION IN PAGE, ARIZONA. 

Respectfully Submitted by:

NATIONAL PARKS CONSERVATION ASSOCIATION,

SIERRA CLUB, GRAND CANYON TRUST, 

SAN JUAN CITIZENS ALLIANCE.

TO NIZHONI ANI

DINÉ CARE

May 5, 2009

The National Parks Conservation Association, Sierra Club, Grand Canyon Trust, San

Juan Citizens Alliance, To Nizhoni Ani and Diné CARE (Petitioners), in accordance with

5 U.S.C. § 553(e), hereby petition the Department of the Interior formally to certify to the U.S.

Environmental Protection Agency that impairment of visibility in Grand Canyon National Park

is reasonably attributable to emissions of oxides of nitrogen and particulate matter from the

Navajo Generating Station. In 1986 the Department of the Interior certified that impairment in

Grand Canyon National Park was reasonably attributable to emissions from the Navajo

Generating Station. Sulfur dioxide scrubbers were installed at the power plant as a

consequence. This petition asks DOI to supplement its 1986 certification based on subsequent

information that shows emissions of nitrogen oxides and particulate matter from the Navajo

Generating Station are also contributing to visibility impairment in the Park. 

I. Background. 

Pollution from the massive Navajo Generating Station (Navajo or NGS) has plagued the

Grand Canyon since coal was first fed to its boilers over thirty years ago. Navajo, located

approximately 12 miles from the eastern edge of Grand Canyon National Park, is the largest
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coal-fired power plant on the Colorado Plateau, and the eighth largest in the country. On an

annual basis, Navajo discharges into the air of the Southwest over 34,000 tons of nitrogen

oxides (NOx), 1,900 tons of particulate matter (PM), 3,690 tons of sulfur dioxide (SO2), and 20

million tons of carbon dioxide. EPA emissions database at

http://camddataandmaps.epa.gov/gdm/index.cfm. Navajo consists of three 750 megawatt units

which became operational between 1974 and 1976. The Salt River Project is the operating

agent for Navajo which is jointly owned by the Salt River Project, the Bureau of Reclamation,

the Los Angeles Department of Water and Power, the Arizona Public Service Company, the

Nevada Power Company, and Tucson Electric Power Company. Existing pollution control

equipment at Navajo includes electrostatic precipitators for PM removal (installed in the

1970s), and SO2 scrubbers (installed in the 1990s). SRP plans to install low-NOx burners at all

three NGS units between 2009 and 2011. SRP estimates that after installation of low-NOx

burners in April of 2011 NOx emissions from NGS will drop from 34,000 tons to approximately

22,000 tons per year – with an associated increase in carbon monoxide emissions of over

36,000 tons per year. EPA Statement of Basis, Low-NOx Burner Project, p. 6, October 2008. 

In 1977, Congress amended the Clean Air Act to provide national parks and wilderness

areas with the highest degree of protection from air pollution. The Grand Canyon National

Park’s resulting “Class I” status meant, among other things, that existing visibility impairment

in the Park would have to be eliminated. 

On November 30, 1979, the Department of the Interior classified Grand Canyon

National Park as a Class I airshed where visibility is an important value. 44 Fed.Reg. 69,122

(November 30, 1979); 40 C.F.R. § 81.403. On November 14, 1985, the Department of the

Interior certified to EPA the existence of visibility impairment in the Grand Canyon Nation

Park, and all other Class I areas within its jurisdiction in the lower 48 States. Attachment 1. 

On March 24, 1986, the DOI sent a letter to EPA which supplemented its earlier certification of

visibility impairment in the Park, and identified the Navajo Generating Station as a probable
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source of impairment. Attachment 2. 

On September 5, 1989, EPA issued a proposed rule preliminarily attributing several

episodes of wintertime visibility impairment in the Grand Canyon National Park to sulfur

dioxide emissions from Navajo. 54 Fed.Reg. 36948. Thereafter, on February 8, 1991, EPA

proposed a Federal Implementation Plan (FIP) that required SRP meet an SO2 limit at Navajo of

0.3 lb/mmbtu on a 30-day rolling average by unit, phased-in by unit in 1995, 1997 and 1999. 

56 Fed.Reg. 5173. As a result of an agreement between SRP, the National Park Service, and

several environmental groups, on October 3, 1991 EPA revised its proposed rule to require SRP

to limit SO2 emissions to 0.1 lb/mmbtu on a plant-wide, rolling annual basis to reduce visibility

impacts in the Park. 56 Fed.Reg. 50172. The scrubbers necessary to meet this limit would be

phased-in, by unit, in 1997, 1998 and 1999. 

EPA’s October 3, 1991 FIP was upheld in 1993 by the Ninth Circuit Court of Appeals

in Central Arizona Water Conservation District v. EPA, 990 F.2d 1531 (9th Cir. 1993). The

Ninth Circuit ruled that a finding of reasonably attributable visibility impairment does not

require EPA to establish “a precise relationship between a [pollution] source’s emissions and

all or a specific fraction of the visibility impairment,” nor is EPA limited to the use of visual

observations to find a given source is responsible for visibility impairment. Id. at 1541. 

By 1999, SRP and the other Navajo owners had completed the installation of SO2

scrubbers at the power plant. According to the National Park Service and other researchers,

since scrubbers were installed at Navajo concentrations of particulate sulfur have dropped

approximately 30 percent during the winter at the Grand Canyon. Journal of Air and Waste

Management, November 2005. 

Unfortunately, the significant reduction in SO2 emissions from NGS has not eliminated

NGS’s impact on the Grand Canyon. To this day, pollution discharged from the NGS continues

to obscure priceless views from both within and outside of the Park. 

Navajo’s present-day impact on visibility in the Park is directly attributable to emissions
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of nitrogen oxide and particulate matter. This is demonstrated by modeling performed by the

National Park Service and SRP, by photographic evidence, and by eye-witness accounts. 

As part of its review of Salt River Project’s November, 2007 Best Available Control

Technology (BART) analysis for regional haze, the National Park Service performed its own

modeling to estimate the impact of Navajo’s current emissions on natural or background levels

of visibility in the Grand Canyon National Park. That modeling showed that NOx and PM

emissions from Navajo alone were causing “gross exceedences” of the Park Service’s

perception criteria in the Park over natural conditions. As set forth in the Park Service’s June

18, 2008, comments to EPA:

NGS presents another unique situation due to its high NOx and PM10 emissions

so close to a Class I area . . . For example, when NPS ran a Level 1 VISCREEN

analysis, our results (Please see Appendix B.1. for additional details.) showed

gross exceedances of the perception criteria in Grand Canyon National Park.

Attachment 3. According to the Park Service’s first level analysis, the particulate matter,

nitrogen dioxide and sulfate emissions from Navajo exceed the Class I visibility screening

criteria for plume color (Delta E) within the Grand Canyon by over twenty times. Id.,

Appendix B.2. The same emissions were found to reduce the visual perception of contrast

within the Park by over two orders of magnitude. Id. Particularly noteworthy is the Park

Service’s finding that SRP’s planned reductions in NOx emissions at Navajo (from 12,661

lb./hr. to 6,570 lb/hr. over the next three years) are plainly insufficient to address Navajo’s

reasonably attributable plume impact on the Park. Id., Appendix A.2. 

Salt River Project’s regional haze CALPUFF modeling, submitted to EPA in 2009, also

demonstrates that Navajo is “causing” visibility impairment in the Grand Canyon (in addition to

other Class I areas). According to EPA’s regional haze regulations, “A single source that is

responsible for a 1.0 deciview change or more should be considered to ‘‘cause’’ visibility

impairment.” 40 C.F.R. Part 51, Subpart P, Appendix Y—Guidelines for BART

Determinations Under the Regional Haze Rule, Section III A. 1. As set forth in SRP’s

modeling, the impact of Navajo’s current emissions on visibility in the Grand Canyon National
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Park on at least eight days in a year is at least 2.5 deciviews – or two and half times greater than

EPA’s causation threshold. Revised BART Analysis for the Navajo Generating Station,

January 2009, p. 3-6. Attachment 4. 

Photographic evidence and eye-witness accounts corroborate the Park Service’s and

SRP’s modeling. That Navajo discharges visible pollution directly from its stacks into the air

of northern Arizona is conclusively shown by the attached September 9, 2007 picture. 

Attachment 5. In the second picture, taken on November 18, 2006 from House Rock Valley

looking northeast, one can see that visibility in the Marble Canyon section of the Park is

significantly impacted by a brown haze of pollution that originates from the stacks of Navajo in

the background. Id. The third picture, taken from Cape Royal on October 23, 2008, shows

similar visibility impairment. The view from Cape Royal to Cape Solitude and the Little

Colorado River Canyon immediately beyond are degraded by a brownish-red layered haze from

Navajo. Id. 

It is well established that nitrogen dioxide (NO2) and PM emissions from Navajo create

an unnatural, reddish brown plume that is visible from many vistas in northern Arizona. 

Navajo emits approximately 34,000 tons per year of NO2, the largest single source of this

pollutant for over 100 miles. According to the Park Service’s 1999 “Introduction to Visibility,”

written by William Malm, “white light will tend to look reddish or brownish in color after

passing through a nitrogen dioxide haze.” Id., p. 10. Long-time residents in the area are very

familiar with the “brown cloud” from Navajo that is a blight on the landscape. 

According to Roger Clark, Grand Canyon Trust’s Air and Energy Program Director,

“I've been visiting, hiking, and rafting the Grand Canyon since the 1950s. Navajo Generating

Station doesn’t emit as much sulfur dioxide as it used to, but its other pollutants continue to

obscure visibility throughout the Grand Canyon region. Its yellow-brown plume still stains the

sky in many directions. It is a rare day when I can’t see its signature blight from Point Imperial,

Desert View, and other prominent Grand Canyon vistas.” 
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II. Petition.

Pursuant to 5 U.S.C. § 553(e) and 40 C.F.R. § 51.302(c)(2), Petitioners formally

petition the Department of the Interior to certify that impairment of visibility in Grand Canyon

National Park is reasonably attributable to emissions of oxides of nitrogen and particulate

matter from the Navajo Generating Station. 

5 U.S.C. § 553(e) states, “[e]ach agency shall give an interested person the right to

petition for the issuance, amendment, or repeal of a rule.” 5 U.S.C. § 551(4) defines the term

“rule” as including, “the whole or a part of an agency statement of general or particular

applicability and future effect designed to implement, interpret, or prescribe law or policy . . .” 

In 1977, Congress amended the Clean Air Act to, among other things, declare:

as a national goal the prevention of any future, and the remedying of any

existing, impairment of visibility in mandatory class I Federal areas which

impairment results from manmade air pollution.

42 U.S.C. § 7491(a)(1). As part of its obligation to meet this goal, EPA was required to

promulgate regulations that included a requirement that:

each major stationary source which is in existence on August 7, 1977, but which

has not been in operation for more than fifteen years as of such date, and which .

. . emits any air pollutant which may reasonably be anticipated to cause or

contribute to any impairment of visibility in any [mandatory Class I] area, shall

procure, install, and operate, as expeditiously as practicable (and maintain

thereafter) the best available retrofit technology . . . for controlling emissions

from such source for the purpose of eliminating or reducing any such

impairment.

42 U.S.C. § 7491(b)(2)(A). 

Pursuant to the regulations promulgated by EPA to remedy existing visibility

impairment, the Federal Land Manager of any mandatory Class I area may certify to the state

(or EPA when the visibility program is implemented through a federal implementation plan as

in Arizona) that it is reasonable to attribute visibility impairment to a single, or small group of

air pollution sources. Accordingly, 40 C.F.R. § 51.302(c)(1) provides that “[t]he affected

Federal Land Manager may certify to the State, at any time, that there exists reasonably

attributable impairment of visibility in any mandatory Class I Federal area.” The term
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“reasonably attributable visibility impairment” is defined as “visibility impairment that is

caused by the emission of air pollutants from one, or a small number of sources.” 40 C.F.R. §

51.301. The term “visibility impairment” is defined as “any humanly perceptible change in

visibility (light extinction, visual range, contrast, coloration) from that which would have

existed under natural conditions.” Id. 

When presented with evidence of visibility impairment in a national park, the Park

Service’s Organic Act establishes an affirmative duty on the part of the Park Service to take

action. According to 16 U.S.C. § 1, 

The service thus established shall promote and regulate the use of the Federal

areas known as national parks, monuments, and reservations hereinafter

specified by such means and measures as conform to the fundamental purposes

of the said parks, monuments, and reservations, which purpose is to conserve

the scenery and the natural and historic objects and the wildlife therein and to

provide for the enjoyment of the same in such manner and by such means as will

leave them unimpaired for the enjoyment of future generations.

(Emphasis added.)

The Park Service has acknowledged this obligation. According to the NPS’s

Management Policy at Section 4.7.1:

The National Park Service has a responsibility to protect air quality under both

the 1916 Organic Act and the Clean Air Act (CAA). Accordingly, the Service

will seek to perpetuate the best possible air quality in parks to (1) preserve

natural resources and systems; (2) preserve cultural resources; and (3) sustain

visitor enjoyment, human health, and scenic vistas. Vegetation, visibility, water

quality, wildlife, historic and prehistoric structures and objects, cultural

landscapes, and most other elements of a park environment are sensitive to air

pollution and are referred to as “air quality-related values.” The Service will

actively promote and pursue measures to protect these values from the

adverse impacts of air pollution. In cases of doubt as to the impacts of

existing or potential air pollution on park resources, the Service will err on

the side of protecting air quality and related values for future generations. 

(Emphasis added.) 

The Secretary of the Interior also has an affirmative duty under Park System Resources

Protection Act to “undertake all necessary actions” to curb air pollution from any source that is

injuring the Grand Canyon National Park. As set forth in the Park System Resources Protection
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Act at 16 U.S.C. § 19jj-2(b)(1), 

The Secretary shall undertake all necessary actions to prevent or minimize the

destruction, loss of, or injury to park system resources, or to minimize the

imminent risk of such destruction, loss, or injury.

As demonstrated above, the Department of the Interior, through its Park Service, should

certify to EPA the existence of visibility impairment in Grand Canyon National Park that is

reasonably attributable to NOx and PM emissions from the Navajo Generating Station. The

Department of the Interior has an affirmative duty to make this certification due to the

overwhelming evidence of Navajo’s air pollution impacts on the Park, and the Department’s

legal obligation to “undertake all necessary actions” to secure the “best possible air quality” in

the Park. 
I. Conclusion. 

It is uncontested that thousands of tons of visibility impairing NOx and PM are 

discharged from the smoke stacks of the Navajo Generating Station every year. Because of 

Navajo's proximity to the Grand Canyon, and the local meteorology, some of this pollution 

inevitably enters the Grand Canyon National Park, marring the beauty of this national treasure. 

Now is the time for the Department of the Interior to take another step in reducing emissions 

from Navajo to benefit this and all future generations. 

DATED: May 5,2009 

FOR PETITIONERS7 

Reed Zah 

Attorney at Law 

9 1 0 Keamey Street 

Larank, IVY 82070 

Cl&n Air Counsel 

MPCA 

706 Walnut Street, Suite 200 

Mnoxville, $N 37902 

865-329-2424 

S tacey Hamburg 

Conservation Program Coordinator 

Sierra Club Grand Canyon Chapter 

3 18 W Birch Ave #8 

Flagstaff7 M 86001 

928-774-65 14 

Roger Clark 

Air and Energy Program Director 

Grand Canyon Trust 

2601 N. Fort Valley Road 

Flagstaff, hzona $600 1 

928-774-7488 
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Mark Pearson

Executive Director

San Juan Citizens Alliance

PO Box 2461

Durango, CO 81302

970-259-3583

Nicole Horseherder

Co-Director

To Nizhoni Ani

P.O. Box 657

Kykotsmovi, AZ 86039

928-380-2687

Anna Fraizer

Coordinator 

Diné CARE

HCR-63 Box 263

Winslow, AZ 86047

928-380-7697

Attachments:

1. November 14, 1985, Department of the Interior certification of impairment. 

2. March 24, 1986, Department of the Interior supplemental certification of impairment. 

3. Park Service’s June 18, 2008, comments to EPA.

4. Revised BART Analysis for the Navajo Generating Station, January 2009, p. 3-6.

5. Pictures showing impairment to Grand Canyon caused by Navajo plume. 
CER'ITLFTCAT'E OF SERVICE 

1 certify that on this "' day of May, 2009, I caused to be sent via overnight courier 

a copy of the foreegoing pelition to the addressees below: 

Secretary Ice11 Salazar Richard Hayslip 

Departlnent of the Intnior Associate General Manager 

1849 C Street, N. W. Salt River Project 

Wasl~ington DC 20240 152 1 N. Project Drive 

Tempe, AZ 85281-1298 

Patrick J. Cuii11i11g11a111 

Acting Director 

Arizona Depal-trueni of' Environmen la1 Qua1 ity 

11 10 W. Washingtul~ St. 

Pl~oenix, AZ 55007 

Lisa Jacltsoi~, Ad111i i? i ~i~~tgiUnited States Eiiviresnnacul31 PI-otcctiur~ Agency 

Ariel Rios Buildir~g 

2 000 Pell~~sylvania Avciiue. N .w. 

Washington, DC 20460 

Laura Y osl-l i i 

Acting Regional Adln~i nistrator 

U.S. EPA Region 9 

75 Hawthon~e Street 

Sail Francisco, CA, 94 1 05 

Stephen B. Etsitty. Executive Director 

Navajo Nation En\:iron~.i?ciit a l Protecl.ion Agaicy 

P.O. Box 339 

Window Rock, Ar-ii~oraa 865 i 5 

The Hopi Tribe 

P.O. Box 123 

TSylcotsmovi, Arizona 8603 9 

Reed Zars