Environmental Injustices of Leaks from Urban Natural Gas Distribution Systems: Patterns among and within 13 U.S. Metro Areas

Abstract

Natural gas leaks in local distribution systems can develop as underground pipeline infrastructure degrades over time. These leaks lead to safety, economic, and climate change burdens on society. We develop an environmental justice analysis of natural gas leaks discovered using advanced leak detection in 13 U.S. metropolitan areas. We use Bayesian spatial regression models to study the relationship between the density of leak indications and sociodemographic indicators in census tracts. Across all metro areas combined, we found that leak densities increase with increasing percent people of color and with decreasing median household income. These patterns of infrastructure injustice also existed within most metro areas, even after accounting for housing age and the spatial structure of the data. Considering the injustices described here, we identify actions available to utilities, regulators, and advocacy groups that can be taken to improve the equity of local natural gas distribution systems.

Investigating high methane emissions from urban areas detected by TROPOMI and their association with untreated wastewater

“…Mobile mapping of urban leaks in 12 urban areas in the USA combined with pipeline infrastructure information from the Pipeline and Hazardous Materials Safety Administration suggest that methane emissions from gas leaks could be five times larger than the estimates in the US Environmental Protection Agency's greenhouse gas inventory [24]. Emissions from gas leaks were further found to be affected by sociodemographic indicators at the level of census tracts indicating inequities in system maintenance [25]. Nevertheless, analysis of top-down and bottomup inventories suggest that some of the discrepancies in the inventories may be due to diffuse methane plumes that could originate 'beyond-the-meter' at the level of individual buildings [26,27].…”

Indoor Air Sources of Outdoor Air Pollution: Health Consequences, Policy, and Recommendations: An Official American Thoracic Society Workshop Report

“…Leaks can occur throughout the system, including at the interface with individual devices, contributing to global warming ( 23 ). In U.S. urban centers, areas with higher percentages of people of color, older homes, and lower incomes have been found to have a higher density of natural gas leaks ( 24 ). A recent study quantified methane released in 53 homes during all phases of stove use: More than 75% of methane emissions occurred when the stoves were turned off ( 25 ).…”

Neighborhood Racial and Economic Composition Predicts Incidence of Various Emergency Service Responses

“…Unlike Weller et al (2022), this work notably includes other types of gas leaks, such as propane leaks. Nonetheless, I expect this recent work to strongly inform the results here.…”

“…In the case of fires, not only are vacant properties at much greater risk for fire, but so are still occupied but deteriorated structures with mechanical defects (Keall et al 2010;Wallace and Wallace 1998). In terms of gas leaks, Weller et al (2022) argue that disparities in infrastructure quality is a key cause of inequality in neighborhood incidence. Similarly, substandard housing has been argued to increase the likelihood of carbon monoxide exposure (Landrine and Corral 2009).…”

“…A small body of research has investigated inequalities in various types of gas leaks. Weller et al (2022) examined 13 U.S. metropolitan areas, finding that income and proportion non-White were strong predictors of natural gas leaks. Notably, these patterns were consistent across most metropolitan areas.…”