1 

U.S. Environmental Protection Agency 

Region 9 

Clean Air Act Permit 

Environmental Justice Analysis

Four Corners Power Plant

Proposed PSD Permit NN 14-01 and Tribal Minor NSR T-002-NN

July 2014 

Introduction

Executive Order 12898, entitled “Federal Actions To Address Environmental Justice in Minority Populations and 

Low-Income Populations,” states in relevant part that “each Federal agency shall make achieving environmental 

justice part of its mission by identifying and addressing, as appropriate, disproportionately high and adverse human 

health or environmental effects of its programs, policies, and activities on minority populations and low-income 

populations.” Section 1-101 of Exec. Order 12898, 59 Fed. Reg. 7629, (Feb. 16, 1994). “Federal agencies are required 

to implement this order consistent with, and to the extent permitted by, existing law.” Id. at 7632. Based on this 

Executive Order, the EPA’s Environmental Appeals Board (EAB) has held that environmental justice issues must be 

considered in connection with the issuance of federal Clean Air Act (CAA) Prevention of Significant Deterioration 

(PSD) permits issued by EPA Regional Offices and states acting under delegations of Federal authority. See, e.g., In re 

Prairie State Generating Company, 13 E.A.D. 1, 123 (EAB 2006); In re Knauf Fiber Glass, GmbH, 8 E.A.D. 121, 174-75 

(EAB 1999) (“Knauf I”). EPA Regional Offices or their delegates in the states have for several years incorporated 

environmental justice considerations into their review of applications for PSD permits. The EAB reinforced the 

importance of completing an environmental justice analysis in a recent opinion discussed further below. See In re: Shell 

Gulf of Mexico, Inc. and Shell Offshore, Inc., OCS Appeal Nos. 10-1 to 10-4, Slip Op. at 63-4 (EAB December 30, 2010) 

(“Shell II”). 

EPA determined that there may be minority or low-income populations potentially affected by its proposed action on 

the Four Corners Power Plant (FCPP) Prevention of Significant Deterioration (PSD) permit application, and 

determined that it would be appropriate to prepare an Environmental Justice Analysis for this action, which is 

provided below. 

For purposes of the Executive Order on environmental justice, EPA has recognized that compliance with the 

applicable National Ambient Air Quality Standards (NAAQS) is emblematic of achieving a level of public health 

protection that demonstrates that EPA’s issuance of a permit for a proposed facility will not have disproportionately 

high and adverse human health or environmental effects on minority populations and low-income populations. See, 

e.g., Shell II., slip op. at 74; In re Shell Offshore Inc., 13 E.A.D. 357, 404-5 (EAB 2007) (“Shell I”); In re Knauf Fiber Glass, 

GmbH, 9 E.A.D 1, 15-17 (EAB 2000) (“Knauf II”); In re AES Puerto Rico, L.P., 8 E.A.D. 324, 351 (EAB 1999). This is 

because the NAAQS are health-based standards, designed to protect public health with an adequate margin of safety, 

including sensitive populations such as children, the elderly, and asthmatics. As the EAB observed, “[i]n the context 

of an environmental justice analysis, compliance with the NAAQS is emblematic of achieving a level of public health 

protection that, based on the level of protection afforded by the NAAQS, demonstrates that minority or low-income 

populations will not experience disproportionately high and adverse human health or environmental effects due to 

exposure to relevant criteria pollutants.” Shell II, Slip Op. at 73. 

The studies assessed by EPA in setting NAAQS and the integration of the scientific evidence presented therein have 

undergone extensive critical review by EPA, the Clean Air Scientific Advisory Committee (CASAC), and the public. 

See e.g., Primary National Ambient Air Quality Standards for Nitrogen Dioxide, Final Rule, 75 Fed. Reg. 6474, 6478 

Feb. 9, 2010. “The rigor of the review makes these studies, and their integrative assessment, the most reliable source 

of scientific information on which to base decisions on the NAAQS.” Id. When setting the NAAQS, “[t]he 

Administrator’s final decisions draw upon scientific information and analysis related to health effects, population 
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exposures, and risks; judgments about the appropriate response to the range of uncertainties that are inherent in 

scientific evidence and analyses; and comment received from CASAC and the public.” Id. at 6483. In light of these 

characteristics of the process for setting the standards, the EAB generally “relies on and defers to the Agency’s 

cumulative expertise when upholding a permit issuer’s environmental justice analysis based on a proposed facility’s 

compliance with the relevant NAAQS in a PSD appeal.” Shell II, Slip Op. at 74. 

Pursuant to Clean Air Act section 165(a)(3), construction of a major emitting facility may not commence until the 

owner or operator of such facility demonstrates, among other things, that the facility will not cause or contribute to air 

pollution in excess of any NAAQS applicable to the PSD permit decision. 42 U.S.C. § 7475(a)(3); see also 40 CFR. 

22.21(k) and 52.21(i)(2). With respect to the proposed permit for the FCPP, the Project does not trigger PSD review 

for any pollutant with a NAAQS, as the Project’s net emissions increases fall below the significant emissions rate for 

those pollutants, including nitrogen dioxide (NO2), volatile organic compounds (VOC), particular matter 10 um in 

diameter and smaller (PM10), particulate matter 2.5 micrometer and smaller (PM2.5), lead (Pb), sulfur dioxide (SO2), 

and carbon monoxide (CO). Generally, EPA Region 9 has looked to compliance with the NAAQS to satisfy the 

Executive Order as to the pollutants regulated under the PSD program. However, for this Project, the only PSD 

pollutant with a significant net emissions increase is sulfuric acid mist (SAM), and EPA has not promulgated a 

NAAQS for SAM. As described in more detail below, EPA has determined that, in this case, it is appropriate to 

review potential impacts associated with the increases in SAM emissions from the FCPP, in order to fully consider 

environmental justice considerations concerning the pollutant regulated under the PSD program that is at issue in the 

present PSD permitting action. 

Project Description 

APS co-owns and operates the FCPP. The FCPP is a coal-fired power plant, utilizing pulverized coal-boilers, located 

on the Navajo Nation about 25 miles west of Farmington, New Mexico. The FCPP currently consists of two 750 

megawatt (MW) coal-fired electric steam-generating units (EGUs), with a total capacity of approximately 1,500 MW, 

and other ancillary equipment such as coal storage, lime handling operations and dry ash handling operations. 

Previously, the FCPP consisted of five coal-fired EGUs. On August 24, 2012, EPA promulgated a source-specific 

Federal Implementation Plan (FIP) requiring the FCPP to achieve emission reductions required by the CAA’s best 

available retrofit technology (BART) requirements.1 In a letter dated December 30, 2013, APS notified EPA that as 

part of the compliance strategy for the BART FIP it would permanently shut down three existing EGUs – Units 1, 2, 

and 3 by January 1, 2014. As of January 2014, the FCPP now consists of the two remaining 750 MW EGUs – Units 4 

and 5 – and the existing ancillary equipment. APS will further comply with the requirements of EPA’s BART FIP by 

installing SCR on Units 4 and 5 to reduce emissions of nitrogen oxides (NOX) by approximately 80% from current 

levels. The installation of SCR to comply with EPA’s BART FIP is causing a significant net emission increase of 

sulfuric acid mist (SAM or H2SO4), which is the reason EPA must obtain a PSD permit from EPA Region 9 for this 

Project. Because the Project causes a significance net emissions increase only for SAM emissions, SAM is the only 

pollutant subject to PSD review for the SCR Project. 

Currently, Units 4 and 5 are each controlled by a wet flue gas desulfurization (FGD) system and a baghouse. The wet 

FGD system is operated primarily to reduce sulfur dioxide (SO2) emissions and is located at the end of the control 

train just prior to the flue gas exiting the stack. Each unit’s baghouse is located prior to the wet FGD and used 

primarily for reducing PM, PM10, and PM2.5 emissions. 

The FCPP SCR Project involves the installation of SCR to reduce approximately 80% of the NOX emissions from 

Units 4 and 5 to comply with EPA’s BART FIP. EPA’s BART FIP requires installation of the SCR systems on Units 

4 and 5 to improve visibility at 16 nearby Class I areas, such as Mesa Verde National Park. The new and affected 

emission units associated with the FCPP SCR Project are: 

· Units 4 and 5 will be modified by adding new SCR emissions controls. SCR will be added to substantially 

reduce NOX emissions. The SCR systems will be located after each EGU’s economizer and before the air 

preheater. 

 

1 For more information on EPA’s BART FIP, please see 77 Fed. Reg. 51620 (Aug. 12, 2012) 
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· Because the SCR emissions controls will cause a significant net emissions increase in SAM emissions, EPA is 

requiring FCPP to install and operate dry sorbent injection (DSI) system as BACT to minimize SAM 

emissions. The DSI system will be located after the air preheater and just before the baghouse and wet FGD. 

· Truck traffic will increase due to the delivery of reagent for the DSI system resulting in increased fugitive 

emissions from paved plant roads. 

· Truck traffic will also increase due to the delivery of urea pellets, 29% aqueous ammonia, or anhydrous 

ammonia for the SCR system resulting in increased fugitive emissions from paved plant roads. 

· A new pneumatic dry sorbent truck unloading system and silo will be installed. 

· A new pneumatic urea pellet truck unloading system and silo may be installed if this reagent option is selected 

for the SCR system or a new ammonia truck unloading station and storage tank will be installed if either the 

aqueous or anhydrous ammonia option is selected for the SCR system. 

Regulatory Framework

The PSD program is a preconstruction review and permitting program applicable to certain new major stationary 

sources and major modifications at existing major stationary sources. The specific requirements under the PSD 

program applicable to stationary sources located in Indian country are in EPA’s Federal Implementation Plan for the 

PSD program at 40 CFR 52.21. The PSD program applies to any regulated NSR pollutant (as defined in 40 CFR 

52.21), except for pollutants designated nonattainment for a NAAQS. The FCPP is an existing major source that is 

located in an area designated as attainment for all NAAQS. Therefore, the PSD program applies if the FCPP SCR 

Project is a major modification for any regulated NSR pollutant. 

The applicability of PSD to a particular source must be determined in advance of construction or modification and is 

pollutant-specific. The primary criterion is whether the proposed project is sufficiently large (in terms of its emissions) 

to be a major stationary source or major modification. If the emissions from a project are greater than the levels that 

are considered a major stationary source or major modification, a PSD permit must be issued before construction of 

the project. 

EPA has determined that a PSD permit is required because the net emissions increase of SAM is above the 

significance threshold of 7 tons per year. In making our applicability determination EPA also considered the 

contemporaneous emission decreases from the shutdown of existing Units 1, 2, and 3. 

In addition to the PSD program, EPA must also consider whether this project is subject to the Minor New Source 

Review Program (NSR) in Indian Country found in 40 CFR 49.151-161. This program includes preconstruction 

permitting requirements for minor modifications at major sources located in Indian country. The requirements of this 

permitting program are triggered based on the applicability criteria contained in 40 CFR 49.153. Based on the net 

emissions increases from the FCPP SCR Project (and consideration of the contemporaneous shutdown of Units 1, 2, 

and 3) EPA determined that the project is not subject to the Minor NSR Program in Indian Country, except for the 

requirement to include increases in allowable emissions in the permit for certain auxiliary equipment associated with 

the Project. 

Overall, the FCPP SCR Project is expected to result in a decrease of approximately 19,000 tons per year (tpy) of 

nitrogen oxides (NOX) and up to a 237 tpy increase in SAM emissions. 

In addition, the PSD permitting program requires that the best available control technology (BACT) be required for 

each emissions unit subject to PSD review. EPA’s proposed permit for the Project includes, among other 

requirements, the use of BACT to limit emissions of sulfuric acid mist (SAM) to the greatest extent feasible. 

Demographics, Public Participation/Outreach Activities, and Air Quality in the San Juan

County

Description of Local Area

Four Corners Power Plant is an existing facility which is located on Navajo Indian Reservation land, half way between 

the towns of Shiprock and Farmington, New Mexico, in San Juan County. The power plant is surrounded by mostly 
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desert land, except for Morgan Lake, which is next to and north of the power plant. Morgan Lake is a man-made 

reservoir, spanning approximately 1,200 acres, and is supplied with water by the San Juan River through an existing 

2.5 mile-long pipeline. The plant site is already served by paved roads, existing transmission lines, pumping station 

pipelines for water and other surrounding, ancillary facilities. The existing ancillary facilities that support the power 

plant include transmission lines, fly ash storage silos, three switchyards, and condenser cooling water intake canals. 

The power plant also has an existing, electric rail line that transports coal from the Navajo mine to the facility. 

The population centers located within San Juan County in the vicinity of the Project site include the unincorporated 

communities of Waterflow, NM (3.79 miles/ 6.1 km north), Fruitland, NM (5.1 miles/ 8.2 km northeast), and 

Kirtland, NM (5.4 miles/8.7 km northeast). Farther out are the town of Shiprock (11.6 miles/18.6 km northwest) with 

a population of 6,380 and the City of Farmington (18 miles/28.9 km east) with a population of 37,117 as of the 2010 

census. 

The facility is located on the Navajo Nation Indian Reservation and there are no other tribes within a 50 km radius. 

Other neighboring tribes within a 100 km radius include the Ute Mountain Indian Reservation to the northwest, the 

Southern Ute Indian Reservation to the northeast, and the Jicarilla Apache to the west of Fruitland. 

Demographic Information

EPA's screening for potential environmental justice concerns focused on an area encompassed by a 25 km radius 

from the proposed facility. This radius includes the primary populations that are expected be impacted by the 

emissions from the Project. However, this size of an area is generally much greater than typically considered for 

community level impacts, so EPA also includes demographic information for areas closer to the proposed facility. We 

included demographic information for areas of 5 and 15 km radii for comparison. These areas are all encompassed 

within the County of San Juan. Thus, to compare information, EPA will present metrics for both San Juan County 

and the State of New Mexico as a whole. 

Demographic information is captured within three radii surrounding the Four Corners Power Plant at 25, 15, and 5 

km2. 

Table 2: Average Demographic Information* for Proposed Project Location and Surrounding Areas

City/Area

Population

Percent

Minority

Percent

Under

Age 18

Percent

Over Age

64

Percent

Linguistic

ally

Isolated

Percent

w/o High

School

Diploma

Median

Household

Income

5 km 436 100 27 6 1 12 $30,586

15 km 8,343 69 28 10 1 11 $38,799

25 km 25,166 79 31 8 1 11 $40,620

Shiprock, NM 6,380 97 29 8 0 9 $29,429

Farmington, NM 37,117 47 30 12 1 9 $56,024

San Juan County 127,517 57 29 11 1 12 $45,822

State of New 

Mexico

2,013,122 59 25 13 2 11 $46,339 

* Population derived assuming uniform population distribution and, therefore, represents an average. 

The three radii closest to the proposed facility (5, 15, and 25 km) capture populations above the state and county 

average for percent minority, and the town of Shiprock also has a higher than County and State average of percent 

minority population. While the population’s minority percentage decreases in the nearby town of Farmington. The 5, 

15 and 25 km radii surrounding the proposed facility capture populations below the County and State average for 

median household income. 

 

2

 U.S. Census Bureau, 2000 and 2010 Data; ESRI, 2012; TANA, 2006; Google, 2012. 
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Linguistic isolation limits a household’s capacity for civic engagement in the regulatory process. 3 Linguistic isolation 

is constant, and relatively low percentage, within the 5, 15, and 25 km distances from the Project, and is below the 

state average for linguistic isolation. The percent of linguistically isolated households in the State of New Mexico is 

2%, as compared with the percent of households located within 5, 15 and 25 km of the Project as well as the town of 

Shiprock and the County of San Juan, which is 1%.4 

Education level is another factor that may influence susceptibility and vulnerability to air pollution. Limited formal 

education is a barrier to employment, health care and social resources, and can increase the risk of poverty, stress, and 

impacts from environmental stressors. The percent of the population over 25 years of age without a high school 

diploma within a 25 km radius of the Project (11%) is equal to the state average of 11%. The percent of the 

population without a high school diploma is similar throughout the area and nearby communities surrounding the 

facility. 

Public Participation/Outreach Activities for EPA’s Proposed PSD Permit Decision

EPA is undertaking a number of actions to provide public participation opportunities to the community for its 

proposed PSD permit decision for the FCPP SCR Project. 

EPA’s proposed permit for the Project, the accompanying Fact Sheet, and the Public Notice will be available for 

review at the following locations: Navajo Nation EPA; San Juan College in Farmington, NM; Diné College, Shiprock 

Branch in Shiprock, NM; Shiprock Branch Library in Farmington, NM; and the Nenahnezad Chapter House in 

Fruitland, NM. Other key documents in EPA’s administrative record for the proposed PSD permit, including the 

permit application, the proposed permit, and EPA’s Fact Sheet, are also available for public review on the EPA 

Region 9 website as well as at the EPA Region 9 office in San Francisco, CA. 

EPA has scheduled two public information meetings followed by public hearings for its proposed PSD permit 

decision: August 27, 2014 at the Nenahnezad Chapter House in Fruitland, New Mexico and August 28, 2014 at the 

San Juan College in the Henderson Fine Arts building, in Farmington, New Mexico. The purpose of the public 

information meeting is to provide interested parties with additional information and an opportunity for informal 

discussion of the proposed Project. The purpose of the public hearings is to provide the public with an additional 

opportunity to provide oral and/or written comments on EPA’s proposed PSD permit for the Project. EPA has also 

prepared a public information sheet for distribution at the hearings that provides a brief overview of EPA’s proposed 

PSD permitting action for the Project. This handout is available on the EPA Region 9 permit website: 

http://www.epa.gov/region9/air/permit/r9-permits-issued.html. 

The notice of the proposed permit is being provided to the public through a wide variety of methods, including the 

following: posting on the EPA Region 9 website; publication in the Navajo Times and the Daily Times, Farmington; 

distribution to a mailing list of those who have requested to be notified by U.S. Mail of any actions related to the 

Project; and distribution by email to those who have requested to be notified by email. While the percentage of 

linguistically isolated households is relatively low in the nearby communities and towns, the native Navajo language is 

Diné Bizaad, and some members of the Diné-speaking population in the nearby communities may prefer to express 

their comments in their native language at the public hearings. In order to encourage participation and aid attendees 

who would like to submit their comments in Diné, EPA is providing a Diné interpreter at both public information 

meetings and public hearings for its proposed PSD permit decision. 

 

3 A linguistically isolated household is defined by the U.S. Census Bureau as a household in which no member 14 years old and 

over (1) speaks only English or (2) speaks a non-English language and speaks English "very well.” In other words, all members 14 

years old and over have at least some difficulty with English. 

4

 San Juan County has one of the highest concentrations in the U.S. of speakers of Native American languages. See Figure 1 of 

Native North American Languages Spoken at Home in the United States and Puerto Rico: 2006–2010 at 

http://www.census.gov/prod/2011pubs/acsbr10-10.pdf. 
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Status of Air Quality in the Area

The FCPP is located within the Four Corners Interstate Air Quality Control Region. San Juan County is currently 

designated as attainment or unclassifiable for all NAAQS: ozone, PM10, PM2.5, NO2, CO, SO2, and lead. 

Impact of Project’s Emissions 

EPA Region 9’s environmental justice analyses for PSD permit decisions usually focus on the potential impacts on 

minority or low income populations from emissions that may affect the NAAQS that are applicable in the PSD 

review for the Project. However, the emissions from this Project are below the significant emission rates for all of the 

NAAQS, and therefore the Project is not subject to PSD review for any NAAQS pollutant. As we noted above, EPA 

has determined that, in this case, it is appropriate to review potential impacts associated with the increases in SAM 

emissions from the FCPP, in order to fully consider environmental justice considerations concerning the pollutant 

regulated under the PSD program that is at issue in the present PSD permitting action. Based on this review, we do 

not expect the emissions increase of SAM associated with the Project to result in adverse human health impacts to any 

population, and therefore we do not expect that our action would have disproportionately high and adverse human 

health or environmental effects on minority or low-income populations, as discussed below. 

At elevated concentrations, SAM emissions can form visible plumes. At some other facilities with wet FGD scrubbers 

like the FCPP, blue SAM plumes have been observed and referred to as plume blight. Physiological responses such as 

eye irritation and breathing difficulty have been reported for episodes involving visible plumes containing SAM 

aerosols at ground level.5 Fine plume problems are expected to occur when SAM vapor or aerosol concentrations 

leaving the ESP or the wet FGD exceed the equivalent of 2 ppmv. These concentrations have the potential to form 

aerosols in the plume that will have an adverse effect on plume visibility and appearance6 – which could then lead to 

adverse health effects. 

In this case, the Applicant’s proposed SAM emission rate of 0.00435 lb/MMBtu is equivalent to 1.5 ppmv, and our 

proposed limit of 0.0025 lb/MMBtu is equivalent to 0.86 ppmv. Given that the Project’s emissions will be well below 

2.0 ppmv, we do not expect any adverse visible plume effects or adverse air quality or human health impacts 

associated with SAM emissions from this Project. We also note that the FCPP SCR Project will result in a reduction 

of 19,000 tpy of NOX emissions. NOX emissions are a precursor to ground level ozone which can make it difficult to 

breathe; cause shortness of breath; inflame and damage airways; and aggravate asthma, emphysema, and chronic 

bronchitis. This reduction in emissions should be beneficial to any nearby populations, including minority or lowincome populations. Based on these factors, EPA has determined that the emissions associated with this Project will 

not result in adverse human health impacts to any population, and that therefore our action would not result in 

disproportionately high and adverse human health or environmental effects on disproportionately high and adverse 

human health or environmental effects on minority populations or low-income populations. 

Conclusion 

Our analysis indicates that the emissions of the pollutant associated with this Project and regulated under EPA’s 

proposed PSD permit for the Project will not result in adverse human health impacts to any population, and that 

there will not be disproportionately high and adverse human health or environmental effects with respect to this air 

pollutant on minority or low-income populations residing near the proposed Project or the community as a whole. 

We also note that our outreach strategy will make information related to our proposed action more accessible to 

nearby communities, including potentially linguistically isolated populations that are primarily Diné speaking. 

Attachments:

· Map of Median Household Income 

· Map of Percent Linguistically Isolated near FCPP 

· Map of Percent Minority near FCPP 

 

5 See Identification of (and Responses to) Potential Effects of SCR and Wet Scrubbers on Submicron Particulate Emissions and Plume Characteristics, EPA-600/R04-107, August 2004, at 2. Available at: http://nepis.epa.gov/Adobe/PDF/P1000OS8.pdf

6 Id. at 59. 
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· Map of Percent over 64 near FCPP 

· Map of Percent under 18 near FCPP 

· Map of Percent without High School Diploma 

· Map of Population Density near FCPP