Nearly a third of Americans—approximately 97 million people—are exposed to harmful, unregulated contaminants in their drinking water. According to a new study by Silent Spring Institute, these contaminants are linked to serious health risks. They disproportionately affect Hispanic and Black communities.
The findings, published in Environmental Health Perspectives, highlight the urgent need for improved water quality regulations. There is also a need for fair resource allocation to address environmental injustices and ensure clean drinking water for everyone.
WHAT ARE UNREGULATED CONTAMINANTS?
Under the U.S. Safe Drinking Water Act, public utilities must check and manage nearly 100 regulated contaminants. Yet, thousands of harmful chemicals remain unregulated, allowing them to enter groundwater and surface water supplies.
Silent Spring Institute researchers analyzed data from the U.S. Environmental Protection Agency’s (EPA) Unregulated Contaminant Monitoring Rule (UCMR) program, which tracks these chemicals. Between 2013 and 2015, 27% of public water systems tested had detectable levels of at least one unregulated contaminant, impacting their drinking water safety.
TOP UNREGULATED CONTAMINANTS FOUND
The study identified four primary unregulated chemicals in drinking water systems affecting millions:
- 1,4-Dioxane
- A probable human carcinogen used as a solvent and found in consumer products.
- PFAS (Per- and Polyfluoroalkyl Substances)
- “Forever chemicals” linked to cancer, thyroid disease, and high cholesterol, commonly found in drinking water supplies.
- Chlorodifluoromethane (Freon 22)
- An ozone-depleting gas used in refrigerants and fluoropolymer production.
- 1,1-Dichloroethane
- A solvent associated with cancer, used in paints, plastics, and pesticides.
These contaminants raise serious health concerns. This is particularly true for communities situated near pollution sources such as industrial sites. Therefore, ensuring the purity of drinking water systems remains a priority.
RACIAL DISPARITIES IN WATER CONTAMINATION
Disproportionate Impact on Communities of Color
The study found that Hispanic and Black residents are more likely to:
- Have unsafe levels of unregulated contaminants in their drinking water systems.
- Live near pollution sources like wastewater treatment plants and industrial discharge sites.
Historical and Systemic Factors
Lead author Aaron Maruzzo attributes these disparities to systemic issues like racism and redlining. These practices historically concentrated industrial facilities in communities of color.
“The percentage of Hispanic and Black residents in a community is a consistent predictor of poorer water quality,” Maruzzo explains.
HEALTH RISKS OF CONTAMINATED WATER
Unregulated contaminants pose significant health risks, including:
- 1,4-Dioxane: Increased cancer risk from drinking water exposure.
- PFAS: Linked to cancer, thyroid dysfunction, and developmental issues.
- Nitrate (Historical Context): Even at levels below federal standards, nitrate exposure can elevate the risk of colorectal and bladder cancer.
These findings underscore the importance of regulating a broader range of contaminants to safeguard public health, emphasizing the need for safe drinking water standards.
PFAS: A GROWING THREAT
PFAS Widespread in U.S. Water Systems
A 2023 Silent Spring study revealed higher levels of PFAS in drinking water systems. These systems serve communities with greater proportions of Hispanic and Black residents. This aligns with newer testing showing PFAS contamination is far more widespread than previously estimated.
EPA’s Response
In April 2024, the EPA introduced drinking water standards for six PFAS chemicals. While this is a step forward, experts like co-author Laurel Schaider argue that more action is needed. They believe more should be done to address the broader scope of unregulated contaminants affecting drinking water safety.
CALLS FOR FEDERAL ACTION
Schaider emphasizes the importance of reducing pollutant discharges into water bodies feeding public water systems. “Ultimately, we need to do a better job at protecting source waters,” she says.
Equity in Environmental Resources
The findings highlight the need for targeted support for communities of color, ensuring equitable access to clean drinking water and resources to mitigate pollution.