February 28, 2011

MEMORANDUM

To: Toxics Rule Docket

From:

Subject: Review of Proximity Analysis

1.0 INTRODUCTION

This memorandum transmits the methods and results of the proximity-based demographic assessment conducted in support of Section J. of the Toxics Rule which regulates coal- and oilfried electrical generation units (EGUs) greater than 25 megawatts (MWs). The objective of the assessment is to determine the demographics of populations located in the vicinity of these EGUs. These populations have the potential to be signi ficantly affected by the emissions of this source category. However, these EGUs usually have very tall emission stacks that tend to disperse pollutants fairly far from the source. In addition, several of the pollutants emitted by this source category (e.g., mercur y (Hg) and sulfur dioxide (SO 2 )) are known to travel long
distances and can cause harm to both the enviro nment and human health as far as hundreds or even thousands of miles from where they were first emitted into the atmosphere. Therefore, while this analysis gives some indication of populations that may be exposed to levels of pollution that can cause concern, it does NOT id entify the demographic ch aracteristics of the people or communities most affected by the pollutant s from this source category or the emissions reductions that would result from this proposed rule.

2.0 ANALYTICAL APPOACH

The following analysis uses the “proximity -to-a-source”approach as a surrogate for potential exposure to identif y those populations living in designated “study areas” around
affected sources. The site location data for the sources subject to the Toxics Rule were taken
from the Office of Air and Radiation’ s Clean Air Markets Divison’s (CAMD) NEEDSv410_NODA database.

Data collected by EPA from potentially affect ed sources in 2010 under the Information Collection Rule (ICR) indicated th at numerous EGUs identified as oil-fired listed in the CAMD database don't fire oil unless they absolutely have to (e.g., when natural gas service is interrupted due to cold weather, hurricanes, etc.). The ICR data also indicated that, given the price differential between natural gas and oil, some “oiled-fired” EGUs had not fired oil in years. In addition, the responses to the ICR revealed that the data on oil-fired EGUs contain multiple miscoding, for example several "oil-fired boilers" were really "combustion turbines" with heat recovery steam generators. As a result of the uncertainities in data on the oil-fired EGUs, wedecided to focus the proximity analysis only on coal-fired EGUs greater than 25 MWs. Therefore the resulting analysis represents appr oximately 97% of likely affected sources (i.e., coal- and oil-fired EGUs) contai ned in the CAMD data base.

The demographic data for this analysis ar e based on census block level data extracted from the 2000 US census which was provided to th e EPA by the US Census Bureau. The sociodemographic parameters used in the analysis include the follow ing categories: Racial (White, African American, Native American, Other or Multiracial, All Other Races); Ethnicity (Hispanic, non-Hispanic); and Other (Number of peopl e below the poverty line).

This proximity analysis determined the demographic composition for two study areas around each emissions source. The first study ar ea consisted of those census blocks whose centriods lay within a 5 km (approxi mately 3 miles) radius of the affected sources. This radius has been used in previous demographic anal yses focused on areas around industrial sources 1,2

. While a 5 km radius has been used in previous ru lemakings, in the case of EGUs it is potentially a poor estimate of the affected area. As noted above, power plants have very tall emissions
stacks that are known to di sperse pollutants broadl y across a large area.

Therefore, this proximity analysis also in cluded a second study ar ea that consisted of those census blocks whose centriods lay within a 50 km (approximately 31.1 miles) radius of the
affected sources. The radius of 50 km was used to approximate the distance from a source where elevated levels of non-mercury hazardous air poll utants such as arsenic and cadimum are most likely to occur. This radius also coincides wi th the maximum dispersion modeling radius used in
the 16 case studies contained in S ection III of the preamble for this rule. It should be noted that neither of these study areas (i.e., the 5 km or th e 50 km radii circles) n ecessarily describe the
individuals or communities with the greatest risk of exposure to mercury from the consumption of fish contaminated by the emissions from EGUs.

During the course of the analysis, we determined that the centroids of some census blocks
were within 5 km or 50 km of more than one coal-f ired power plant. This meant that the analysis ran the risk of “double counting.” This was part icularly problematic as the study areas expanded
from 5 km to 50 km. We resolved this issu e by counting each census block only once when aggregating the summary data for each study radi us. The summary data presented in Table 3.1
are based on "absolute" numbers that elimin ate any double counting.

3.0 SUMMARY OF THE DEMOGRAPHIC ANALYSES

The proximity analyses indicate that All Other Races’share of the population living within a 5 km of coal-fired EGUs is higher than the national average. For these same areas, the percent of African Americans a nd the percent of th e population below the poverty line are also

1 Mohai P, Saha R. “Reassessing Raci al and Socio-economic Disparities in Environmental Justice Research.” Demography. 2006; 43(2): 383–399. 2 Mohai P, Saha R. “Reassessing Raci al and Socio-economic Disparities in Environmental Justice Research.” Demography. 2006; 43(2): 383–399.slightly higher than their respective nationa l averages. The specific values for these demographic variables compared to their respecti ve national averages are as follows: All Other Races - 29.2% v 24.9% respectively; African Amer ican - 15.8% v. 12.3% respectively; Hispanic - 15.5% v. 13.7%, respectively, and number belo w poverty level - 15.6% v. 13.1% respectively.

The demographic characteristics of the popul ation living within 50 km of coal-fired EGUs is different. Although the percent of All Other Races remains slightly above the national average (i.e., 25.5% v. 24.9%, respectively) as do es percent African Am ericans (i.e., 15.2% v. 12.3% respectively), the percent of Other and Mu ltiraicial (including Native Americans), and the percent of the population living below the poverty line decrease below th eir respective national averages. In addition, it should be noted that the analysis indicates that 75% of Americans live
within 50 km of at least one coal-f ired EGU. (See Table 3.1 below.)

Table 3.1 COMPARATIVE SUMMARY OF THE DEMOGRAPHICS WITHIN 5 KM (3 MILES) AND 50 KM (31 MILES) RADII OF THE AFFECTED SOURCES

Nationwide 5 Km (3 mile) Study Area 50 Km (31.1 mile) Study Area Total population 285,339,125 6,558,259 214,108,152 Race by percent

White 75.1 70.8 74.5

All Other Races 24.9 29.2 25.5 Race by percent

White 75.1 70.8 74.5

African American 12.3 15.8 15.2

Native American 0.9 0.7 0.5

Other and
Multiracial 11.7 12.7 9.7

Ethnicity by percent Hispanic 13.7 15.5 9.9 Non-Hispanic 86.3 84.5 90.1 Below Poverty Line by percent Below poverty level 13.1 15.6 11.6 Above poverty level 86.9 84.4 88.4