Oakland's Leona Creek to lose odd orange hue after cleanup Long-abandoned mine turns water orange - cleanup finally planned

Laura Post checks out the abandoned sulfur mine that has been contaminating the creek near her Oakland home. Laura Post checks out the abandoned sulfur mine that has been contaminating the creek near her Oakland home. Photo: Sarah Rice, Special To The Chronicle Photo: Sarah Rice, Special To The Chronicle Image 1 of / 7 Caption Close Oakland's Leona Creek to lose odd orange hue after cleanup 1 / 7 Back to Gallery

In a city with many oddities, there's nothing quite like Oakland's Leona Creek: It's bright, foaming and stinking orange.

Some neighbors describe it as the Love Canal, or the River of Tang. Others keep their pets and kids away. Some are so used to it they think it's normal.

But normal it's not. The creek is awash with sulfuric acid, sometimes at levels comparable to battery acid, leaching from an abandoned pyrite mine near the creek headwaters in the Oakland hills. It flows through Mills College and past O.co Coliseum, and ultimately empties into San Francisco Bay.

But now, 84 years after the Leona Heights Sulfur Mine closed, the site is finally slated for cleanup. The state's Regional Water Quality Control Board threatened to fine the owner $10,000 per day until he ensures the creek runs clear.

Cleanup is expected to begin in May and end by October. A community meeting is slated for Thursday in Oakland.

"I'll be happy when it's just a normal creek," said Ron Post, an engineer who lives next to the mine. "It's always struck us as a little dangerous. ... When we first moved in, it made us nervous. We didn't know what it was."

Residents around Leona Creek are among the state's luckier mine neighbors. California is pockmarked with more than 47,000 abandoned mines, according to the state, 11 percent of which are environmental hazards. But so far, few of them have been cleaned up.

Because about half the mines are on private property, cleanup orders can be a lengthy and convoluted process, said Keith Roberson, senior engineering geologist with the state water quality board.

"California, like most Western states, has a long history of abandoned mines. In most cases, the mines are no longer owned by the people who made them," he said, noting that matters are further complicated because dozens of government agencies can be involved. "But finally, the time has come where we're making mine cleanup a priority."

The Leona Heights Sulfur Mine operated from about 1900 to 1930, one of dozens of mines around the Bay Area. Miners dug pyrite from the hillside and sent it to a chemical company in Richmond for conversion to sulfuric acid, a common chemical that's used to make explosives, batteries, detergents and other items. It's also used in oil refining.

The remnants of the Leona mine resemble a miniature Grand Canyon, an orange and barren gouge in the hillside. Tunnels, old rail cars and wooden sheds litter the property.

At the bottom of the mine, adjacent to the Posts' driveway, are piles of sulfur-rich rocks left over from mining operations. When rainwater washes over the rocks, it carries the sulfur into the creek, where it becomes sulfuric acid and corrodes the metals along the creek bed.

That's where the orange comes from. On a visit Friday morning, the creek was neon orange, with bubbling white eddies and a distinct rotten-egg odor. The creek runs orange for about a mile before the sulfur neutralizes.

The Post family had their water - which comes from a nearby spring - tested before they moved in 22 years ago. The test revealed nothing toxic, and they have experienced no problems associated with the creek or the old mine. In fact, it's been a favorite spot for kids in the neighborhood searching for chunks of pyrite and other treasures.

"It's nothing I would drink, but in a way it's sort of cool," Ron Post's wife, Laura, said. "We never really knew that much about it."

The creek is toxic to wildlife, however. Deer, skunks, possum, foxes, raccoons, coyotes and other animals abound in the Oakland hills, and ingesting water from Leona Creek would be fatal.

"Most animals know not to drink from it. The real issue is that the creek is a dead zone," said Lindsay Whalin, a geologist with the water quality board. "Wildlife should be able to rely on that creek for fresh water."

The cleanup will consist of a large plastic sheet over the mine and nearby rock piles, topped with soil and plants to separate water from the sulfur. Crews will also haul away some of the mining debris from Leona Creek and add vegetation.

The lining should stay intact for at least 1,000 years, Whalin said.

The property owner, Oakland surgeon Collin Mbanugo, is paying for the cleanup. He did not return phone calls Friday. Because of the mine and the instability of the hillside, the property cannot be developed, Whalin said.