This just in, Clear Lake, located in northern California (and for that matter, several other lakes in that region) is quite possibly the most mercury polluted lake in the world, reports the Associated Press. A history of silver mining throughout the area has left many of the lakes polluted and the fish highly toxic, if consumed.
And it gets worse, the people most affected are some of the poorest in the area. Mercury, once it has contaminated a lake, is nearly impossible to remove. You would have to dreg and clean the bottom soil which besides being very complicated is also nearly impossible to do. Clear Lake has been the recipient of mercury poisoning from what is now a Superfund site since before the 1950s. The Sulfur Bank Mine closed operations in the 1950's and while California has spent two decades and close to $40 million USD to clean it up, mercury is still leaching into the lake.
The Elem Band of Pomo Indians colony was built over waste from the mine in the 1970s before it was a known Superfund site. Now, mercury levels in their blood test higher than people from the area who don't eat tainted fish. Many people in the community have moved out of the area, and the government has spent millions removing dirt from homes and roadways that might be contaminated.
The sad thing is that the US government has been able to clean up less than a dozen of the hundreds of abandoned mines in the state. In most cases, the mines have not even been studied so no one knows the actual extent of contamination and where and how far the pollution is leaching. Even worse, no one knows just how many mines are out there - with some estimates at 550 and others ranging as high as 2,000 abandoned mines. Owners of these former mines want nothing to do with them, if they can be contacted at all, thus the government is going bankrupt trying to deal paying for cleanup of all of these mines.
The poor are most at risk because they tend to be subsistence fishers, eating fish with 10 times the level of mercury than what is deemed "safe." Mercury pollution doesn't just harm those closest to the mine. In fact, mercury pollution is one of the biggest sources of pollution for both the San Francisco Bay and the Sacramento-San Joaquin River Delta. According to one EPA official, "it took a hundred years to occur, and it may take a hundred years or more to solve." :Associated Press