MEMORANDUM

To: Docket EPA-HQ-OAR-2011-0081: Response to Petition from New Jersey 

Regarding SO2 Emissions from the Portland Generating Station

From: Martha Keating, Geographic Strategies Group, OAQPS, US EPA

Doug Solomon, Geographic Strategies Group, OAQPS, USEPA

Arthur Zuco, Community and Tribal Programs Group, OAQPS, USEPA

Date: September 7, 2011

Subject: Environmental Justice Assessment for Section 126 Petition from New Jersey 

Regarding SO2 Emissions from the Portland Generating Station

1.0 Executive Summary

Executive Order 12898 (59 FR 7629, February 16, 1994) establishes Federal executive 

policy on environmental justice (EJ). Its main provision directs Federal agencies, to the greatest 

extent practicable and permitted by law, to make EJ part of their mission by identifying and 

addressing, as appropriate, disproportionately high and adverse human health or environmental 

effects of their programs, policies, and activities on minority populations and low-income 

populations in the United States.

EPA defines “environmental justice” to include meaningful involvement of all people 

regardless of race, color, national origin, or income with respect to the development, 

implementation, and enforcement of environmental laws, regulations, and polices. 

This memorandum describes the approach EPA used to identify potential EJ communities 

in counties impacted by sulfur dioxide (SO2) emissions from the Portland Generating Station 

located in Northampton County, Upper Mount Bethel Township, Pennsylvania. The areas of 

highest impact were identified by air quality modeling as summarized in the proposed rule (76 

FR 19662) and as described in detail in the Modeling Technical Support Document, which can 

be found in the public docket for this rulemaking.

1

 1

Geographic Information Systems (GIS) 

software was used to identify and summarize the demographic makeup of the population 

residing in areas near the facility.

http://www.regulations.gov EPA-HQ_OAR-2011-0081
EPA has determined that this action will not have disproportionately high and adverse 

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

demographic data illustrates that the population residing near the source is represented by fewer 

minority and low-income residents than either the surounding counties, the average demographic 

composition of the States of New Jersey and Pennsylvania, and national averages. In addition, 

this rule increases the level of environmental and public health protection for all affected 

populations since, when fully implemented, it will result in attainment of the health-based 1-hour 

SO2 national ambient air quality standard (NAAQS).

Section 2 of this memorandum describes the Portland Generating Station and provides an 

overview of the air quality modeling results. Section 3 describes the GIS methodology used to 

identify the appropriate census block and block groups relevent to this analysis and the sources 

of the underlying census data. Section 4 summarizes the findings of the demographic analysis, 

Section 5 discusses meaningful involvement of the affected communities, and Section 6 provides 

conclusions. 

2.0 Facility Description and Overview of Air Quality Modeling Results

The Portland Generating Station is a 427 megawatt (MW) coal-fired power plant located 

in Upper Mount Bethel Township in Northampton County, Pennsylvania. Within 500 feet and 

directly across the Delaware River is Knowlton Township in Warren County, New Jersey. The 

facility includes two main boilers, an auxiliary oil-fired boiler, and 3 small turbines which burn 

oil and natural gas. The facility is bordered to the north and northwest by terrain higher than any 

of the stacks at the Portland Station.

On April 7, 2011, EPA proposed to find that SO2 emissions from the Portland Station are 

contributing to nonattainment and interfering with maintenance of the 1-hour SO2 NAAQS in 

New Jersey. EPA also proposed emission limits and compliance schedules to ensure that the SO2

emissions from the facility are sufficiently reduced to mitigate the interstate transport and nonattainment issues in the neighboring county.

The basis for EPA’s proposed emission limits were the results of EPA’s independent 

modeling assessment of the Portland Station’s SO2 emissions. Allowable emissions were 

modeled using the AERMOD dispersion model to estimate the impacts of the facility’s 

emissions on ambient air quality. The area modeled around the plant (receptor grid) was selected 

based on an assessment of meteorological data including prevailing wind direction and wind 
speed, terrain, and results of a preliminary (coarse grid) modeling assessment to ascertain the 

approximate area of maximum impact. 

Figure 1 depicts the modeling grid used to assess ambient air impacts due to SO2

emissions from the plant.2 The grid stretches 5 kilometers (km) (~3 miles) north of the plant, 4 

km (2.5 miles) east, 1 km (0.6 miles) south, and 2 km (1.2 miles) west. The modeled maximum 

99th percentile (4th-highest daily maximum 1-hour SO2 concentration during the period 2007-

2009) is used to compare ambient levels with the 1-hour SO2 NAAQS value of 75 ppb or about 

196 ug/m3. The highest modeled value from the Portland Station was 851.1 ug/m3 and is located 

northeast of the facility. In addition, as shown in Figure 1, while other “corners” of the grid show 

lower modeled emissions, every point in the grid shows modeled SO2 levels that are higher than 

the 1-hour SO2 standard of 196 ug/m3

. 

 2 Air Quality Modeling Technical Support Document: NJ 126 Petition. Air Quality Assessment Division, U.S. 

Environmental Protection Agency. EPA 454/R-10 March 2011. 

Figure 1. Modeling grid and AERMOD results for Portland Station
3.0 GIS Methodology and Data Sources

As described above, EPA’s AERMOD modeling indicated that SO2 concentrations that 

exceed the 1-hour SO2 NAAQS extend beyond the ranges of modeling grid. Consequently, the 

EJ analysis was not constrained to the geographic area of the modeling grid. Using GIS, the 

location of the facility and county and state boundaries were mapped. Within counties, census 

block groups surrounding the Portland Station were also identified. A census block contains 

about 50 people on average; a census block group contains about 26 blocks on average, or about 

1,350 people. The purpose of assessing the larger block groups was to include potential at-risk 

populations outside of the modeling domain and to compare the demographics of these 

populations to county and state populations. However, to be certain that using census block 

groups for the EJ analysis did not skew the demographic results (by averaging over a larger 

geographic area) we also conducted the analysis at a finer scale. Specifically, census blocks 

within a 3- and 5-mile buffer around the Portland Station were identified and the demographic 

data summarized for the entire buffer area. This supporting analysis is presented in Appendix A. 

3.1 Determining Census Block Groups for Analysis

As shown in Figure 2, the areas included in this analysis are those six census block 

groups (numbered 1through 6) that are intersected by the boundary of modeling domain and two 

census block groups (numbered 7 and 8) adjacent to boundary of the modeling domain. The 

block groups were identified using an intersect analysis. The intersect analyses were performed 

using the GIS product, ArcMap®, part of ESRI Corporation’s ArcGIS® version 10 line of 

products.3

(1) The modeling domain boundaries were imported to ArcView® and ArcView®’s

intersect tool was used to identify census block groups with any portion intersected 

by the AERMOD modeling domain, and 

). The basic steps followed are: 

(2) A visual inspection of the modeling domain and census block groups was used 

identify and add two additional census block groups (number 7 and 8) located just 

outside the modeling domain in Warren County, New Jersey.

In all, three block groups in Northampton County (PA) and five block groups in Warren 

County (NJ) were assessed. The geographic range of the EJ analysis extends roughly 15 km (~ 

 3 http://www.esri.com/software/arcgis/arcview/key-features.html
10 miles) northeast, 11 km (~ 7 miles) east, 9 km (~ 6 miles) south, and 14 km (~9 miles) west of 

the Portland Station. These distances are greater than the radius of 5 km (~ 3 miles) that has been 

used in other demographic analyses focused on areas around potential sources.4,5,6,7

3.2 Census Data

 In addition, 

since the air modeling analysis did not indicate where the ambient air concentrations of SO2

decline to acceptable levels, a demographic analysis of all of Warren County, NJ and 

Northampton County, PA was also conducted to be inclusive of a larger geographic area around 

the facility.

Census data from the U.S. Census Bureau, 2000 Decennial Census were used in this 

analysis for determining population and socioeconomic demographics. Data for the block groups 

were aggregated for race, ethnicity, age, educational level and poverty status (Figure 2). Block 

group level data for population and race were obtained from the Population and Housing

Summary File 3 (SF3). The SF3 contains sample data, which is information compiled from the 

questions asked of a sample of all people and housing units that were surveyed in the 2000 

Census. The dataset includes racial and ethnic classifications, age, income, educational level, 

poverty status, language, home value, and population totals for foreign born and ancestry groups. 

4.0 Demographic Results

Table 1 summarizes the results of the demographic analysis. The data are presented 

separately for the block groups that are located in Northampton County, Pennsylvania and the 

block groups that are located in Warren County, New Jersey. Since multiple block groups were 

assessed for each county, average values for the assessed block groups within each county was 

calculated. The averages for these block groups are listed as well as averages of county data

(Warren, New Jersey and Northampton, Pennsylvania), state data (Pennsylvania and New Jersey)

and the entire U.S. 

 4 U.S. GAO (Government Accountability Office). Demographics of People Living Near Waste Facilities.

Washington DC: Government Printing Office; 1995.

5 Mohai P, Saha R. “Reassessing Racial and Socio-economic Disparities in Environmental Justice Research”. 

Demography. 2006;43(2): 383–399. 6 Mennis J. “Using Geographic Information Systems to Create and Analyze Statistical Surfaces of Populations and 

Risk for Environmental Justice Analysis”. Social Science Quarterly, 2002;83(1):281-297. 7 Bullard RD, Mohai P, Wright B, Saha R, et al. Toxic Waste and Race at Twenty 1987-2007. United Church of 

Christ. March, 2007. 
Figure 2. Block groups (numbered and outlined in gray) proximate to Portland 

Station that were selected for demographic analysis.

5.0 Meaningful Involvement

Included in the definition of “Environmental Justice” is the principle that EPA will 

include meaningful involvement of all people regardless of race, color, national origin, or income 

with respect to the development, implementation, and enforcement of environmental laws, 

regulations, and polices. For this action EPA published notice of the action in the Federal 

Register on April 7, 2011. The notice also included information on a public comment period for 

submittal of written comments and announced a public hearing. The public hearing was heald on 

April 27, 2011 in the Pequest Trout Hatchery and Natural Resources Education Center located in 

Warren County, New Jersey. Information about the hearing was also announced by the New 

Jersey Sierra Club8

, the Facebook page of Knowlton, New Jersey9, the MSP Alliance website10, 

and on the NJ.com website.11

 8 https://secure3.convio.net/scnj/site/Advocacy?cmd=display&page=UserAction&id=909
Environmental justice concerns were not raised by any member of the public either at the 

hearing or in writing to the public docket during the public comment period.

6.0 Conclusions

The results of the demographic analysis, as summarized in Table 1, illustrate that EPA’s 

proposed action (i.e., reducing emissions of SO2 from the Portland Station) will have neither a 

disproportionate nor adverse impact on minority or low-income populations. The demographic 

data illustrate that the population residing near the source is represented by fewer minority and 

low-income residents than either the surrounding counties, the average demographic composition 

of the States of New Jersey and Pennsylvania, or national averages. The percent of population 

between 0 and 17 years of age, the percent of population below poverty level, and the percent 

without a high school diploma are all lower in areas in proximity to the facility compared to 

county, state, and national averages. The percent of population older than 64 is slightly higher in 

the 3 blocks groups assessed in Northampton, Pennsylvania compared to county and state 

populations. As shown in Table 1, the average percent of population older than 64 in the 3 block 

groups in Northampton County was 17 percent compared to an average of 15 percent in 

Northampton County as a whole and the State of Pennsylvania.

Since this rule, when fully implemented, will result in attainment of the health-based 1-

hour SO2 NAAQS in areas proximate to the Portland Station and consequently increases the 

level of environmental and public health protection for all affected populations, EPA has 

determined that this action will not have disproportionately high and adverse human health or 

environmental effects on minority or low-income populations.

 9 http://www.facebook.com/notes/knowlton-nj-on-njcom/epa-to-hold-public-hearing-in-oxford-tomorrow-onpennsylvania-power-plant-air-em/206069752758193 10 http://www.mspnews.com/news/2011/04/07/5431804.htm 11 http://www.nj.com/warrenreporter/index.ssf/2011/04/epa_to_hold_public_hearing_in.html
Table 1. Summary Results of Demographic Analysis

Demographic Summary White African 

American

Native 

American

Other or 

Multiracial Hispanic or Latino Age < 17 Age > 64

No High School 

Diploma

Below 

Poverty 

Level

Pennsylvania

Average of 3 

Block Groups in 

Northampton 

County (PA)

98% 1% 0% 1% 2% 21% 17% 18% 6%

Northampton 

County (PA) 86% 5% 0% 5% 11% 22% 15% 19% 8%

Pennsylvania 82% 11% 0% 5% 6% 24% 15% 18% 11%

New Jersey

Average of 5 

Block Groups in 

Warren County 98% < 1% 0% 2% 1% 26% 12% 13% 3%

Warren County 

(NJ) 90% 4% 0% 4% 7% 23% 14% 15% 5%

New Jersey 69% 14% 0% 11% 18% 25% 13% 18% 8%

United States 75% 12% 1% 12% 14% 27% 12% 13% 13%
Appendix A 

Demographic Buffer Analysis of Portland Station

As described in Section 3.0 above, an alternative finer-scale demographic analysis was 

conducted to ensure all potential at-risk populations surrounding the Portland Station were 

identified. In this analysis a 3- and 5-mile buffer was identified and, using the same data sources 

as described above, demographic data for all block groups whose centroid was located within the 

buffer were summarized. Figures A.1 and A.2 present the buffers and location of the population 

centroids with the 3- and 5-mile buffers, respectively. 

Figure 1.A. Block Centroids within 3 miles of Portland Generating Station
Figure 1.B. Block Centroids within 5 miles of the Portland Generating Station

Table A.1 summarizes the results of this analysis. As shown, the results of the finer-scale block 

analysis are essentially the same as those presented above for the block group analysis. Thus, the 

conclusion that that EPA’s proposed action (i.e., reducing emissions of SO2 from the Portland 

Station) will have neither a disproportionate nor adverse impact on minority or low-income 

populations is further reinforced.
Table A.1. Summary Results of Buffer Demographic Analysis

POPULATION WHITE AFRICAN 

AMERICAN

NATIVE 

AMERICAN

OTHER OR 

MULTIRACIAL

HISPANIC 

OR LATINO1 AGE 0 - 17 AGE > 64

NO HIGH 

SCHOOL 

DIPLOMA

BELOW 

POVERTY 

LEVEL

NEAR SOURCE TOTAL (3 miles) 4,487 4,363 25 7 92 122 1,086 622 508 228

% OF NEAR SOURCE TOTAL 97% 1% 0% 2% 3% 24% 14% 11% 5%

NEAR SOURCE TOTAL (5 miles) 10,214 9,977 59 8 170 213 2,543 1,448 1,134 503

% OF NEAR SOURCE TOTAL 98% 1% 0% 2% 2% 25% 14% 11% 5%

NATIONAL TOTAL 285,339,128 214,539,706 35,043,873 2,489,515 33,265,937 39,083,760 77,355,207 35,412,451 36,657,905 37,118,454

% OF NATIONAL TOTAL 75% 12% 1% 12% 14% 27% 12% 13% 13%

Sources: The demographics are from the U.S. Census Bureau, 2000. Information on the facilities is from U.S. EPA.

1. The Census Bureau defines “Hispanic or Latino” as an ethnicity rather than as a racial category, Hispanics or Latinos may belong to any race.

DEMOGRAPHIC SUMMARY