State and local authorities have targeted Almaden Valley’s riverbanks for some massive cleanups this year. In July, state water authorities approved a 70-year plan to help safeguard San Francisco Bay from mercury, and Almaden is considered one of the most challenging areas in the cleanup.
State water authorities in July approved a 70-year plan to help safeguard San Francisco Bay.
This summer, a team from the Santa Clara Valley Water District got a head start on the cleanup prior to the state’s approval and completed a mercury extraction and bank stabilization project at the Guadalupe River near Camden Avenue in Almaden. Crews also started a project on the banks upstream near McKean Court and Harry Road.
“Instead of waiting for the regional board to decide, we are getting out in front of it,” said Beau Goldie, deputy operating officer for Santa Clara Valley Water District.
The New Almaden Mine was one of the largest mercury mining projects in the world during the 1800s, and its environmental impact is still felt. Runoff from the mines has gathered in Guadalupe River, flowing through San Jose into the bay.
Guadalupe River winds through a number of San Jose communities, including Willow Glen, downtown San Jose and the Rose Garden on its way to the bay.
Mercury was used in the past century in gold-finding processes and as an ingredient in products such as paint and thermometers, but it has been replaced because of health concerns.
Prolonged human exposure to methyl mercury causes nerve damage in fetuses, among other problems, according to the Environmental Protection Agency.
In response to health and environmental concerns, the state Water Resources Control Board approved a plan July 17 to limit the amount of mercury that reaches the bay. The plan limits annual mercury deposits to 700 kilograms. The old standard was 1,200 kilograms. Researchers will test fish to determine if these levels have been met.
Tom Mumley, assistant executive officer for the San Francisco Bay Regional Water Quality Control Board, said the cleanup will take 70 to 100 years. Board officials have been meeting with officials from the valley water authority, Santa Clara County, landowners and environmental groups leading up to the decision.
“We consider it one of our biggest accomplishments in terms of our mission to protect the environment,” Mumley said. “It’s not like we’re done, but it’s a major step in solving a very complicated problem.”
Since 2001 in San Jose, the valley water district has been lifting sediment out of Guadalupe River to stop erosion and maintain the waterway. During the process, crews also remove mercury from the soil.
The district also has tried to control methyl mercury in Lake Almaden and in the Calero, Guadalupe and Almaden reservoirs. Solar-powered circulators churn the water in Lake Almaden to limit mercury buildup in insects.
The valley water district has spent more than $2.6 million on the project so far, mostly with money from the Clean Safe Creeks fund approved by Santa Clara County voters in 2000. District officials say they have enough money to continue the cleanup for a few more years, but another county tax effort appears likely. Officials are informally calling it Clean Safe Creeks 2.
Consumer water rates are separate from money spent on the cleanup.
Most of the heavy toxins from the New Almaden Mine have been cleaned up with federal money, Mumley said, but it will take decades to rid San Jose’s watershed of the mercury that put it on the map.
“As they used to say,`there’s a lot of mercury in them thar hills,’ ” Mumley said, “and it’s going to take a long time to get it out of the bay.”
