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San Gabriel groundwater is the "most contaminated"

San Gabriel Valley groundwater has the highest organic matter contamination statewide, according to findings of a recent study from the US Geological Survey.

The study, which found contamination in both San Fernando and San Gabriel valleys at more than nine times the rate as elsewhere in the state, is the first to quantify the amounts. It traces the contamination back to commercial pollution. In a majority of the wells, geologists found significant levels of dry cleaning solvents and compounds like Atrazine, a popular herbicide which has been banned in the European Union.

“Anthroprogenic compounds, that is, man-made compounds, have been found in 100% of the water wells tested," said Jason Kulongoski, the research hydrologist who headed the study of San Gabriel and San Fernando valley groundwater. He said that the San Gabriel Valley groundwater basin is “unique to any other basin” in that “it is the most contaminated basin as far as organic constituents go.”

Another disturbing discovery was high concentrations of perchlorate, a contaminant byproduct of the rocket industry, found in 11 percent of well samples in both San Fernando and San Gabriel valleys.

High concentrations of toxic solvents had previously been identified as polluting both the San Fernando and San Gabriel Valley water basins. “What’s new to this particular study is not the high concentrations we found,” said Dr. Kulongoski. “What’s new is that we quantified it.”

Despite the findings, residents are not at risk by drinking aquifer water, says Dr. Kulongoski. The contaminated aquifer water is diluted with safe water or is carbon filtered before being delivered for public use and the plumes are being treated by regional water masters in conjunction with the Environmental Protection Agency.

Still, the USGS findings give weight to new water legislation in Sacramento.

Citing Californian’s lack of clean water access, Assemblyman Mike Eng, who represents the San Gabriel Valley, is sponsor of a bill that declares access to clean water a human right. The bill makes it a state priority to protect all California groundwater from contamination, calls for the improvement of drinking water quality, and aims to identify the water needs of disadvantaged communities.

Assemblyman Eng said that the bill does not intend to take away any existing water cleanup responsibilities from the EPA but intends to unite state agencies working on water quality to “the ultimate goal of allowing every person in the state to have access to clean, affordable water.”

More information from KPCC: Toxic chemicals 9 times as concentrated in San Fernando, San Gabriel valleys than elsewhere in California

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1 thought on “San Gabriel groundwater is the "most contaminated"”

  1. When we moved to Alhambra in the 70’s there was a similiar report about contaminated ground water so I had water delivery for drinking mainly & every so often in my water bill I get information explaining that “Alhambra water is clean, safe to drink” & I have been thinking of stopping my water delivery, but after this report I’ll continue playing it safe – but why does the water district LIE about “clean drinkable water: when this report contradicts them? I don’t supposse I’ll get an answer to my conern.

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