It’s been 40 years since a mercury mine in San Benito County closed. Finally, the Environmental Protection Agency is cleaning it up. For KAZU, Leslie David reports on the project and why it took so long.
A jumble of rickety buildings sits halfway up an arid canyon in southern San Benito County. This and a few homes are all that’s left of the once booming mining town of New Idria. In its heyday, New Idria was the second most productive mercury mine in the nation. “The mining industry was well and booming when I first went into it. Mining was going strong, and we were producing raw material for the country,” said Mark Ward. The 85-year-old worked at the mine in New Idria for nearly two decades.
The mine went out of business in 1972. Once it became clear the owner had no plan to clean it up, County Officials tried to get the Environmental Protection Agency to step in. San Benito County has boxes documents detailing its near forty year effort to address New Idria. San Benito County Director of Waste Management Mandy Rose says the EPA showed little interest because New Idria is isolated and has a small population. “We kept being relegated to the bottom of the pile because we were not affecting human beings at that time,” said Rose.
What moved New Idria to the top of the pile was a new understanding of mercury, a neurotoxin that affects coordination and memory. UC Santa Cruz PhD candidate Priya Ganguli studied New Idria. Her research showed that the mercury at the mine could potentially work its way into a nearby creek and into the bottom of the food chain. “And that continues along the food web up to your high level predators including humans, and so that the organisms at the top of the food chain will end up with concentrations that can be a million times higher than the mercury concentration in the water in which those critters are living,” said Ganguli. Late last year, the EPA finally named New Idria a Superfund site. This means the agency will clean it up and try to get the company that mined here to pay for it.
Outside the mine, the EPA’s Kelly Manheimer watches as a backhoe digs a ditch. It’s diverting an orange colored water, called acid mine drainage, from the mine opening to a bed of limestone. “The acid mine drainage, of course, is toxic because it is very low PH. So it’s acidic and that’s what we’re trying to address with the limestone before it goes into the creek,” said Manheimer. The limestone acts as a filter. It removes the orange iron and reduces the water’s acidity. Manheimer walks to the nearby creek to show the results. “This is San Carlos Creek. As you can see not red, not orange, looking very healthy,” said Manheimer. Another major component of the clean-up is addressing the millions of rocks left over from mining. The rocks still contain mercury. “What I would like to see is all of the areas where currently you will see the bright red rock that was calsines, the roasted ore, would be covered with vegetation,” she added. Over time, plants and soil will cover the rock, keeping the mercury in place. Manheimer says it will be at least five years before the whole project is complete.
Former New Idria employee Mark Ward hopes something will be left to tell the story of mining in California. “That’s all gone now. I don’t know of any mining camps like that left anymore in the United States. It’s all gone.” It’s unknown if any of the New Idria mine buildings will remain.