Superfund Site Report for Board
Lake County Supervisors will meet at 9 a.m. Tuesday, March 9, at the Lake County Courthouse, 255 N. Forbes St., Lakeport.
LAKEPORT - Lake County supervisors next Tuesday will hear a major report on the Superfund cleanup of a mercury mine contaminating Clear Lake, hub of the county's vital tourist industry.
At 10 a.m., a federal official is scheduled to describe the alternatives and costs for neutralizing the complex Sulfur Bank Mercury Mine on the east shore of Clear Lake's Oaks arm.
Project Manager Rick Sugarek will present information from a two-inch thick feasibility study that will be available to the public in April. After a public comment period, the U.S. Environmental Protection Agency will choose its plan.
Design work will begin perhaps in the summer. Design and construction will take about 10 years. Then what is built will begin operating.
There is no one approach to the mess, says Raymond Ruminski, county environmental health director. The 120-acre site is a patchwork of waste rock, ore piles, mine tailings (residue) and the 23-acre Herman Impoundment, a 90-to-100-foot open pit mine now filled with an acidic poisoned lake.
About 193,600 cubic yards of waste remain. The tailings, which look like common dirt or gravel, extend along 1,300 feet of shoreline.
The impoundment surface is higher than Clear Lake. So it leaches its water downward through poisoned geology, carrying mercury and arsenic and other unwholesome substances into the county's recreational treasure.
Part of the cleanup will involve lowering the impoundment level below the lake's, so the flow will be reversed. Lake water flowing down to the impoundment won't hurt anyone, Ruminski points out.
Contaminated water from elsewhere on the site can be pumped into the impoundment after its level drops below the lake.
Options for containing the mine wastes include earthen caps and liners. Other measures must block or divert runoff that carries toxic material to the lake. Some mine waste can be permanently stored in on-site repositories.
One option mentioned is industrial reuse of site water, for instance, for geothermal injection.
Once off the site, mercury and arsenic settled into the lake bottom sediments, where it feeds plants, which feed fish and other organisms, which is why health officials warn against eating the fish.
When the site cleanup is done, the next task is to clean out the contaminated lake sediments.
The Elem Indian Colony, on the land tip adjacent to the impoundment, is dealing separately with the EPA. The Bureau of Indian Affairs allowed mining companies to use Elem land.
The area was mined for sulfur from 1865 to 1868. Mercury ore was mined underground from 1899 to 1902 and 1915 to 1918.
Early in the 20th century, Ruminski says, miners converted to strong, mechanized equipment, and mined from open pits in 1922-1947 and 1955-57. During those periods, waste containing mercury was dumped directly into Clear Lake and along the shoreline.
Depending on the alternative designs and their effectiveness, construction cost estimates range from about $9.8 million to $37.3 million. Yearly operation and maintenance estimates range from $165,000 to $815,200.
The people or companies that polluted the lake should pay, says Ruminski, but "the guys who did this have been dead for 40 to 50 years."
Other items before the board Tuesday:
* At 9:06 a.m., supervisors are scheduled to consider the costs of wage increases for In-Home Supportive Services Workers. The workers' union has been negotiating for an increase above the current minimum wage. Whether or not the county can afford the increases has been a contentious issue. A county report said it could lose millions of dollars.
A consultant's report says the county could get enough in federal and state reimbursements to handle an increase.
The state is supposed to reimburse the county's share of the in-home workers' pay, 21 cents of every dollar. That could be at risk, the consultant says.
* At 11:20 a.m., supervisors are scheduled to consider a contract for an economic development project to help the local pear industry.