Analysis - The Institute for Southern Studies

7D. Child Population Statistics (Executive Order 13045)
Purpose of Child Population Data Analysis
Under Executive Order (EO) 13045 of 21 April 1997, Federal Agencies shall make it a high priority (a) to identify and assess environmental
health and safety risks that may disproportionately affect children, and (b) shall ensure that its policies, programs, activities, and standards
address disproportionate risks to children that result from environmental health or safety risks. Although the EO does not define children, the
US Census Bureau defines “children” as follows 190 :
Children: The term "children"… are all persons under 18 years, excluding people who maintain households, families, or
subfamilies as a reference person or spouse.
The purpose of this section is not to evaluate children risks, but to evaluate whether disproportionate percentages of children live near electric
utility plants. This analysis involves a 5-step process for comparing children population data for each electric utility plant location, to statewide
children population data to identify whether children disproportionately reside in geographic areas where electric utility plants are located.
Collection of Child Demographic Data
Step 1:Plant address 5-digit “Zip Code Tabulation Areas” (ZCTAs) formed the geographic basis for this child population data collection.
Because ZCTAs represent irregularly shaped geographic areas, this ZCTA based data collection may be considered a “screening level”
analysis. The US Bureau of Census uses over 33,000 ZCTAs for its Census counts of population and other demographic statistics based
on the US Postal Service’s over 42,000 nationwide ZCTAs. 191 Currently, there are no size restrictions limiting how large or small a
ZCTA can be in terms of either a minimum/maximum number of housing units or geographic area. Any particular ZCTA may be as
small as a few city blocks or may cover many square miles. Many ZCTAs are for villages, census-designated places, portions of cities,
or other entities that are not municipalities. The nationwide average ZCTA population is about 7,200 persons (i.e., (306.6 million mid-
2009 US population) / (42,500 ZCTAs)). The nationwide average ZCTA area is about 83 square miles (i.e., (3,536,278 square miles
total US land and water area) / (42,500 ZCTAs)), which is a land area equivalent to a 5-mile radial distance (i.e., ((83 square miles) /
(3.1416))^0.5). In comparison, the radial area monitored for contamination in response to the December 2009 TVA Kingston TN
electric plant CCR spill is reportedly four miles, 192 and this average 5-mile ZCTA radial distance falls between the 1-mile to 15-mile
radial distances used by EPA’s Superfund “Hazard Ranking System” (HRS) 193 to define affected populations of sites having either (a)
soil contamination only (1-mile), (b) groundwater and/or airborne contamination (4-miles), or (c) surface water contamination (15-miles
190 The US Census Bureau definition of “children” is from its “Current Population Survey (CPS) - Definitions and Explanations” website at:
http://www.census.gov/population/www/cps/cpsdef.html
191 Source: US Census Bureau ZIP Code Tabulation Area (ZCTA) Frequently Asked Questions.: Nationwide total ZCTA count is from the US Postal Service’s FAQ
website at: http://zip4.usps.com/zip4/welcome.jsp
192 Source: 4 mile radial monitoring area reported by Waste & Recycling News, 13 Feb 2009; http://www.wasterecyclingnews.com/email.html?id=1234543579
193 More background information about EPA’s HRS is available at http://www.epa.gov/superfund/programs/npl_hrs/hrsint.htm.
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