Spatial Distribution of Leaking Underground Storage Tanks in Charleston, South Carolina: An Environmental Justice Analysis

Purpose: To evaluate spatial distributions of leaking underground storage tanks (LUSTs) in the Charleston Metropolitan Statistical Area (MSA). We aimed to use various Geographic Information Systems (GIS) techniques that could provide local policymakers and community groups with knowledge to make better decisions for revitalization, planning and community development efforts.

Methods: GIS was used to ascertain the demographic profile of populations burdened by LUSTs in the Charleston MSA: 1) mean distance analysis, 2) spatial coincidence, and 3) proximity analysis. Linear regression models were applied to examine the association between distances to the nearest LUST facility and proportions of whites in census tracts. Chi-square tests were conducted to compare differences of race/ethnicity and SES between census tracts that host LUSTs and those void of LUSTs.

Results: Census tracts that host LUSTs are predominantly non-white populations and have lower SES status while those that do not host LUSTs are mostly white populations and have higher SES status. Results from the buffer analysis indicated that over 99% of the black population in the Charleston MSA was captured by a LUST buffer. Furthermore, as percent non-white increased, the number of LUSTs increased respectively. Census blocks in Metro Charleston with a higher proportion of white residents (> 50%) were approximately 1.11 miles away from the nearest LUST while primarily non-white census tracts were 0.86 miles.

Conclusion: There are significant burden disparities in the distribution of LUSTs in Charleston MSA at the block and census tract levels across varying levels of demographic composition for race/ethnicity and SES. This may lead to exposure risks for underserved populations and increase risks of cancer and other negative health outcomes for differentially burdened populations.