Study Highlights California Groundwater Contaminants

By: Nathan Lamb

Groundwater from the southern California desert has higher-than-average levels of naturally occurring contaminants, according to this story from the Desert Sun newspaper.

A recently released study from the U.S. Geological survey found contaminants in 42 percent of aquifers from the Coachella Valley, which is roughly 100 miles west of Los Angeles. The study found high levels of arsenic, boron, fluoride, molybdenum and strontium—all of which have been linked to adverse health impacts by the Environmental Protection Agency. The study did not evaluate samples from water utilities, which are subject to health regulations and often treat groundwater to remove contaminants.

A spokesperson from the Coachella Valley Water District stated their treated drinking water is in full compliance with health regulations, saying they average 18,000 quality tests annually. And Miranda Fram of the USGS groundwater monitoring program explained that "water delivered to [residents] meets water-quality standards.”

The U.S. Geological survey was billed as the most extensive evaluation of desert groundwater to-date, with the goal of getting a comprehensive picture on the issue. The study also evaluated acquirers in the Owens, Indian Wells and Antelope Valleys, along with the Mojave area and Colorado River basin.

Across the desert, contaminants were found in 35 percent of groundwater tapped by public drinking supplies, whereas the average ranges from 10-25 percent across most of the state. The report suggested that water typically stays underground longer in the desert, giving it more time to mix with contaminants.