There are 2 million tons of toxic waste scattered across an area that includes 15 miles of wetlands. Not much is left of the town of New Idria. It was once the largest and one of the most productive mercury mines in the country. At its height, 2,000 people called New Idria home. Now, only a handful remain, largely because of the toxic legacy that was left behind.
New Idria was a pioneer in mining. Its furnaces were the first of their kind and are credited with revolutionizing ore processing. The mine opened in the 1850s to supply gold miners with mercury, allowing them to quickly separate gold from earth.
"Mercury was used for many different purposes, from thermometers, to switches, to the nuclear industry," explained EPA Regional Director Jared Blumenfeld.
When the mine closed in 1971, it left behind at least 30 miles of underground tunnels that now leak water loaded with mercury.
"This was a site that wasn't regulated well in any way, shape or form, and is now a Superfund site," Blumenfeld said.
The EPA first started looking into mercury levels at New Idria in the early 1990s and called for Superfund status last year.
"EPA has Superfund sites around the country. It really means that this is the most toxic of the toxic sites, and we're committed to making sure it's cleaned up no matter what the cost," Blumenfeld said.
That cost is expected to be in the range of $10 million and take decades to complete. Clean-up work is expected to begin this fall.
"Initially, what we're going to try to do is eliminate or at least minimize the damage caused by the acid mine drainage that you see behind me, the bright orange water that's creeping around everywhere," explained project manager Kelly Manheimer.
The plan is to carve two channels to divert rain runoff from mixing with the toxic mine water. Then, work will then begin on a pipeline that will funnel the mine's water into a pond.
"We will settle out some of the metals and the mercury before it discharges then into San Carlos Creek," Manheimer added.
Water from San Carlos Creek feeds the San Joaquin River, which in turn makes its way to the delta and ultimately, into San Francisco Bay. Prolonged exposure to mercury can damage the nervous system in people and it has been found at elevated levels in some fish.
Biologist Jenny Marek with U.S. Fish and Wildlife says there are several threatened and endangered species in the area.
Superfund status means tax money will be available to the U.S. Fish and Wildlife Service to investigate the potential impact of that toxic runoff.
"We're in an arid area and the perennial water source is this stream that's contaminated with mercury. So, any time you have a water source in an arid area, wildlife are going to be attracted to it," she said.
The Bureau of Land Management will also benefit from Superfund status. It owns the land surrounding New Idria. On that land, there are half a dozen other mines.
"They're connected with this complex, and we wanted to coordinate our efforts in a partnership with the EPA so we could save costs," explained BLM geologist Tim Moore.
By the way, New Idria is listed as a California Historic Landmark, a designation that must be considered as part of the clean-up process.
Written and produced by Ken Miguel