Socioeconomic Disparities in Sea Level Rise Impacts on Wastewater Treatment Plants

Many of the United States' major cities that have a high population are located along the coast. The number of people residing in low-elevation coastal areas, below 10 m, is increasing. Coastal areas may be affected by various short- and long-term climate hazards, such sea-level rise (SLR). Climate change induced SLR will threaten residents and infrastructure in low-lying coastal areas. A household's capacity to respond to hazards is highly dependent on their socio-demographic situation that determines their social vulnerability. Wastewater treatment facilities is a particularly critical piece of infrastructure often located in low-lying areas due to gravity fed collection systems. Additionally, flooding of these infrastructure systems can lead to spread of disease and contamination of water sources In this analysis, we utilized a geographic information systems to assess the exposure of wastewater infrastructure to sea level rise projections in the contiguous United States. We then paired these inundation estimates against the Center for Disease Control's Social Vulnerability Index (SVI) to investigate inequities in infrastructure impact. An analysis of variance (ANOVA) was performed to compare the SVI of populations near wastewater treatment plants that were inundated to those that were not inundated at sea level rise projections. Of the 1,040 wastewater treatment plants within 2 km of the coast in the United States, 394 treatment facilities are in danger of inundation at 10 feet of sea level rise. Interestingly, the results of the ANOVA tests revealed no statistical difference in social vulnerability indexes of impacted populations and infrastructure against non-impacted populations.