In a concerning trend for water utilities and public health officials, a recent study reveals that drought conditions are exacerbating drinking water contamination in California's Latino/a communities. This disparity presents significant challenges for water management professionals and policymakers.
Community water systems (CWSs) serving majority Latino/a populations in California consistently show higher levels of nitrate and arsenic contamination compared to those serving non-majority Latino/a communities. The gap is widening, with nitrate concentrations in groundwater-sourced drinking water for majority Latino/a CWSs rising from 2.5 mg/L in 1998 to 3.1 mg/L in 2018. Conversely, levels in non-majority Latino/a CWSs decreased from 2.1 mg/L to 1.8 mg/L over the same period.
Drought conditions intensify these disparities, particularly in surface-sourced drinking water. For CWSs serving over 75% Latino/a populations, a 2-unit increase in the normalized drought index correlates with a 0.16 mg/L rise in nitrate concentrations. This effect is most pronounced in very small and privately operated CWSs, suggesting these systems may lack the resources or infrastructure to effectively mitigate contamination during drought periods.
As climate change increases the likelihood of severe droughts, the water quality gap may continue to grow. Surface-sourced water, which serves nearly 80% of the population, shows a drought-related increase in nitrate levels more than double that observed in groundwater sources. This trend is particularly alarming given the long-term health risks associated with exposure to contaminants like arsenic and nitrate, including increased risk of cancers, cardiovascular diseases, and developmental disorders.
Water utilities and policymakers must prioritize support for vulnerable CWSs, particularly those serving Latino/a communities, to ensure they can maintain water quality standards during drought conditions. This may involve investments in treatment infrastructure, operational support, and technical assistance tailored to the unique challenges faced by these systems.
The disparities revealed in this study have far-reaching implications for water management professionals and policymakers. Beyond arsenic and nitrate, vulnerable CWSs may face increased risks from other contaminants during natural events like droughts and floods. This highlights the need for comprehensive water quality monitoring and management strategies that account for both demographic factors and climate-related stressors.
To address these challenges, a multi-faceted approach is needed. This may include developing drought-resilient water sources, improving treatment technologies, and implementing more robust water quality monitoring systems. Additionally, policymakers should consider how to allocate resources more equitably to ensure that all communities have access to safe drinking water, regardless of demographic composition or system size.
