Summary of Excess Manganese Discovered in California’s Water:
A new study has found that excessive amounts of naturally occurring manganese in drinking water put low-income communities in California’s Central Valley at risk. High levels of manganese have been linked to neurological symptoms such as tremors, muscle rigidity, developmental issues, and liver and kidney damage over the long term. The highest manganese concentrations were found in private, untreated well water systems. Researchers estimate that nearly half of all domestic well water users in the Central Valley live in disadvantaged communities. Despite this, manganese is only regulated as a secondary contaminant in the US, with no enforceable maximum limit.
*****
Manganese Contamination in Drinking Water is Disproportionately Harming Low-Income Communities in California’s Central Valley
Introduction
Manganese, a naturally occurring element, is vital for human health in small amounts. However, excessive exposure to manganese in drinking water can lead to severe health consequences, including neurological symptoms and liver and kidney damage. Scientists have recently discovered excessive amounts of manganese present in the drinking water of California’s Central Valley. The highest concentrations were found in private untreated well water systems, with public water systems also containing levels high enough to cause adverse health effects.
Disproportionate Harm to Low-Income Communities
The UC Riverside-led study also found that the population at risk of manganese contamination is concentrated in low-income communities. Nearly half of California’s Central Valley domestic well water users live in disadvantaged communities. Furthermore, almost 89% of this population is highly likely to access contaminated water with manganese.
Treatment Options are Costly
Point-of-use treatment options for manganese-contaminated water range from oxidation and precipitation filters to water softeners, chlorination, and reverse osmosis systems. However, these devices for monitoring water quality can cost up to $400 annually, and treatments for manganese-tainted water are just as expensive. Communities would require subsidies to purchase them.
Digging Deeper Wells is Unlikely to Help
The researchers also found that manganese-contaminated groundwater tends to occur in shallow depths, making it unlikely that digging deeper wells would avoid contamination.
Regulation of Manganese in Drinking Water
Manganese is not regulated as a primary contaminant in the United States but is only held as a secondary contaminant with no enforceable maximum limit. This means that the number of wells considered safe may be greatly overestimated. The benchmark used by the researchers to assess water quality was 300 parts per billion of manganese. Some studies associate this level of manganese contamination with neurological development issues, particularly for fetuses and infants during early growth. Conservative studies from Canada, where manganese is now a primary contaminant, show that adverse effects can occur at 100 parts per billion.
Conclusion
The regulation of manganese as a primary contaminant and enforceable maximum limit is necessary to ensure safe drinking water for all Californians. The UC Riverside-led study focused on California’s Central Valley, where manganese contamination is prevalent. However, similar manganese contamination in drinking water is likely to present in other parts of the state. Over 1.3 million Californians rely on unmonitored private wells, making the population being exposed much more significant than initially thought. The communities most affected are low-income and marginalized populations who need subsidies to access treatment options.
Comments are closed