|A new UC Berkeley/UCLA study, Inequities in Drinking Water Quality Among Domestic Well Communities and Community Water Systems, California, 2011‒2019 has found that an estimated 370,000 Californians rely on contaminated drinking water sources that disproportionately impact communities of color in the state. |
The study examines both community water systems and domestic well areas of California, covering about 99 percent of the state’s population by race and renter status, and looked at three contaminants and their average concentration for a nine-year period (2011-2019): naturally-occurring arsenic, nitrates, and chromium-6, all of which are toxic to humans, and using available water quality data from the state OEHHA.
The study found:
For arsenic, nearly twice the proportion of people on domestic wells (about 8.2 percent) face levels exceeding the average allowable concentrations than do people on larger community water systems (about 4 percent).
Similarly, mean nitrate concentrations exceeded regulatory limits in over twice the population of domestic well users (4.3 percent) than for people on community water systems (about 1.6 percent).
A greater share of community water systems had a larger proportion of chromium-6 contamination (about 6.7 percent) than did domestic well areas, probably due to their location closer to former industrial areas which leaked chromium-6 into soils adjacent to their community systems.
The researchers found associations between arsenic concentration and residents reliant on domestic wells. Renters on domestic wells, who are generally poorer than home owners, also were closely associated with greater rates of exposure to these contaminants.
Cumulative contamination by these chemicals, the researchers found, was higher in the San Joaquin Valley than for the state as a whole. Their Valley definition included San Joaquin County domestic well areas and community water systems. The County makes up about 40 percent of the legal Delta region.
Restore the Delta says:
Ensuring that ALL Californians have clean drinking water should be the first priority of all California water resource agencies. This report reveals how we have invested in the wrong priorities in California for proper water management, and how badly communities of color have been neglected in terms of water management priorities, historically. It is unacceptable.
Restore the Delta wants the State to right the wrongs of the past and to plan for a resilient water future with climate change. We believe these priorities need to be worked on simultaneously.
1. Focus on rebuilding local water systems to provide clean and affordable drinking water for all Californians, giving first priority to communities of color, and communities with inadequate drinking water systems.
2. Build nature-based flood control systems that will protect flood-vulnerable communities, especially environmental justice communities, from catastrophic flooding due to increase severity of storms due to climate change. Nature-based flood control systems will also help to restore groundwater systems for environmental health and drinking water supplies.
3. Implement water conservation, recycling, and reuse projects everywhere possible. This includes re-landscaping California for a drought tolerant future.
4. Prioritize restoring watersheds so that salmon fisheries can thrive and so that water supplies for domestic water use are safe, clean and protected.
5. Bring water use into true balance with demand. We must do the hard work of transforming economies that can no longer be sustained by unlimited use of water.