Addressing Drinking Water Supply as an Environmental Justice Issue in North Carolina
Many households in North Carolina rely on well water, especially in rural regions underserved by public water supplies. Notably, historical practices in the state excluded areas with a significant racial minority population from public water supply access.
Earlier in 2022, UNC researchers uncovered a distressing reality–thousands of wells across the state are tainted with toxic metals.
Toxic metals of particular concern in North Carolina wells include arsenic, cadmium, manganese and lead. Exposure to these contaminants has been associated with severe health issues, including cancer, kidney impairment, cardiovascular problems and neurological disorders.
It’s essential to note that the Environmental Protection Agency (EPA) enforces limits on these metal concentrations in public drinking water systems exclusively.
“Our previous research on private well water has unveiled thousands of tests exceeding EPA limits for arsenic, manganese and lead,” says Rebecca Fry, PhD, Carol Remmer Angle Distinguished Professor and Interim Chair in the Department of Environmental Sciences and Engineering and principal investigator of these NIEHS-funded studies. “Recognizing historical injustices that have marginalized racial minority communities and forced them to rely on private wells motivated us to develop the toxic metal environmental justice index.”
Developing the Toxic Metal Environmental Justice Index
This innovative index factors in both socioeconomic disadvantages and environmental exposures. It consists of two key values, mirroring aspects of the EPA’s EJScreen: a demographic index value derived from census tract records and an index representing environmental exposures, particularly toxic metals found in well water.
To calculate the demographic value for each census tract, researchers compared the proportions of minority populations and low-income households to the state’s overall figures. Census tracts with a higher proportion of minorities and low-income households have a positive value, while those with fewer such households receive a negative value.
To determine the environmental exposure index, researchers leveraged the NCWELL database, a comprehensive repository of over two decades of well water test results across North Carolina. Using this database, they gauged how many tests in each census tract exceeded EPA limits for arsenic, cadmium, manganese, and lead.
A higher number of contaminated wells per tract contributed to a higher environmental exposure index value. By combining the demographic index with this data, researchers could identify areas with a high proportion of minorities or low-income households and significant well contamination.
Using the Index to Identify Vulnerable Areas
Researchers calculated index values for all census tracts across the state, with a particular focus on areas exhibiting positive index values. These are areas with a higher proportion of minority and low-income households and elevated levels of metals in well water.
Notably, most of these positive values were observed in the eastern part of the state and in regions bridging urban and rural areas. Furthermore, researchers identified counties with a high number of census tracts displaying positive environmental justice index values, highlighting the elevated risks faced by these communities.
Addressing Environmental Injustice: A Call to Action
The research concentrated on areas with a higher concentration of low-income and minority communities to uncover potential environmental injustices. While it was found that areas with a lower proportion of low-income and minority residents also faced elevated levels of well contamination, the index is instrumental in highlighting the need for support in resource-scarce regions where residents grapple with contamination issues.
Social disadvantages present unique challenges in improving the quality of well water, as solutions such as filter installations may not be financially feasible for many low-income individuals. Going forward, the research team aims to refine the index further with updated census data and incorporate this information into the NC Enviroscan tool, developed by the UNC Superfund Research Program and community stakeholders.
The researchers hope that state and county officials will utilize this index to identify communities requiring remediation or additional well testing to mitigate residents’ exposure to toxic metals.
Contact the UNC Gillings School of Global Public Health communications team at sphcomm@unc.edu.
