370,000 people are drinking contaminated water in a state where access to safe, clean water is a legal human right.
A new study from the University of California, Berkeley published the findings last week in the American Journal of Public Health. Led by Rachel Morello-Frosch, professor of public health and environmental science, policy, and management at UC Berkeley, and Laura Cushing, an assistant professor of environmental health sciences at the University of California, Los Angeles, the study marks the first quantitative analysis of water quality and demographics across the state.
Access to safe, clean, and affordable drinking water is a human right in California, which legislates that community water systems must undergo regular testing to mitigate potential harmful chemicals in the water. Previous research suggests that these water systems often do not meet regulatory standards, and additionally, 3.4% of Californians rely on water from domestic wells, which are unregulated.
The team’s data collection focused on three known contaminants, chosen for their toxicity and prevalence. Arsenic is commonly found in groundwater and is concentrated when a water table dries; nitrate is usually found in agricultural runoff, a significant issue in California; and hexavalent chromium is a byproduct of industrial manufacturing activity. Researchers gathered water samples from across the state, including both domestic wells and community water systems.
Their findings estimate that over 370,000 Californians rely on contaminated drinking water or drinking water with the level of one or more of the three contaminants above the regulated standard. Of those 370,000, over 40% received their water from a domestic well
Cushing and Morello-Frosch didn’t just measure water quality, but they sought to understand how demographics play into clean water disparities across the state. Using census data, they found that people of color were more likely to be supplied with contaminated water.
“This pattern has already been documented in community water systems, particularly in the San Joaquin Valley, but our work is one of the first to examine the question statewide and among domestic well communities not served by public water system,” Cushing said.
The researchers want to use their findings to influence future public health policy in the state. They have already created the Drinking Water Tool, a website for community members and policymakers to understand the scope of the issue. People can use the website to identify where their water is sourced and if it may be contaminated. They hope that this data will pressure the state to increase water testing and inform potential solutions. For instance, legislators can investigate whether consolidating water from domestic well areas and community water sources will allow more people access to clean water.
Cushing stressed the urgency of this problem. “In this era of climate change, our groundwater is becoming an increasingly precious resource, and we're facing historic levels of drought and well failures. Even if a well doesn't fail, drawdown of the water table can impact water quality by concentrating contaminants, making these problems even worse,” she said.