The board will meet beginning at 9 a.m. in the board chambers at the Lake County Courthouse, 255 N. Forbes St. TV Channel 8 will broadcast the meeting live; it will also be available later in the week online at http://laketv8.pegcentral.com/.
University of California, Davis scientists have requested time on the board agenda to present the findings from their work on mercury in Clear Lake. The item is timed for 9:15 a.m.
The 18 papers – which recently were published in scientific journals – are the result of a 15-year study of Clear Lake. They can be found online at www.esajournals.org/toc/ecap/18/sp8?cookieSet=.
Scientists, funded in part by the Clear Lake Environmental Research Center and the US Environmental Protection Agency Superfund account, focused primarily on the Sulphur Bank mercury mine in Clearlake Oaks and its impacts on Clear Lake. The researchers state that the mine was in operation from 1873 to 1957. It is now a Superfund site.
Concerns about mercury and its potential impacts on humans and the environment are the focus of significant scientific research efforts around the world, several researchers – led by Thomas Suchanek – noted in the paper, “The legacy of mercury cycling from mining sources in an aquatic ecosystem: From ore to organism.”
However, few studies have focused specifically on mercury bioaccumulation resulting from mining; the researchers noted that a US Environmental Protection Agency mercury to report to Congress, submitted in 1997, didn't identify mining as a significant environmental mercury source.
Yet the researchers note that mercury, gold and silver mines continue to play a major role in releasing mercury into the environment, “and some progress is being made toward understanding these processes.”
They go on to explain the California is home to nearly 300 abandoned mercury mines and prospects, mostly along the Coast Range. The paper explains that, over the past 150 years, mercury contamination from Coast Range mines “has been, and continues to be, deposited into streams that join either directly or indirectly with the Sacramento River, the San Joaquin River, and the San Francisco Bay-Delta estuary.” The mercury that came from the Coast range mines was used in the Sierra Nevada for silver and gold mining.
Methylmercury, a toxic compound that can result from released mercury, can remain stable within sediment from “decades to millenia,” the researchers note.
And, while they state that Clear Lake is one of the world's most mercury-contaminated lakes, that is qualified with the additional finding that the resulting methylmercury concentrations aren't as high as predicted.
The “mine-derived acid mine drainage” is responsible for ongoing dissolved mercury loading, but that hasn't translated to high toxicity levels, the researchers found.
Scientists also have found that mercury residues in tissues of grebes from museum specimens were higher than those found in more recent samples, which tells that them mercury reaching the lake's birds “was already in a declining phase at the beginning of our studies in 1992.”
Incidentally, in 1992 the EPA began an emergency removal action to reduce erosion of mercury-laden rock into the lake, according to the paper. That work doesn't appear to have slowed the flow of acid mine drainage into Clear Lake.
From 1992 to 2005 osprey nests grew from seven to more than 30 in the Clear Lake area, making it comparable to Eagle Lake near Susanville, a lake the researchers say has no mercury contamination. Those improvements may have been more due to management practices, with mercury residues in osprey feathers noted to once again increase during that time. In 2004, mercury concentrations in juvenile largemouth bass showed the highest mercury concentrations in a 30-year period.
The paper also refers to a study of 63 residents of the Elem Colony of Pomo Indians. Mercury levels in their blood were found to be “significantly higher that he average U.S. Population,” which was correlated to fish consumption. At least 10 percent of those surveyed consumed more fish than suggested by advisory guidelines established in 1987, researchers found.
The board also will consider a proposed amendment to the joint operating agreement between the Lake County Sanitation District (LACOSAN) and Northern California Power Agency to allow use,
occupancy and access of LACOSAN property for a solar energy facility (Bear Canyon Zero). As part of the item, the board also will consider a proposed lease and easement agreement between LACOSAN and Northern California Power Agency. The item is set for 9:10 a.m.
Last month the county officially launched a 2.2-megawatt solar installation that is partially located on LACOSAN property in both the north and south county.
Other agenda items follow.
Timed items:
10 a.m.: Assessment appeal hearing: Mediacom California LLC, seeking assessments on unsecured accounts/tax bills on 13 parcels throughout Lake County.
10:15 a.m.: Consideration of staff recommendation on proposed criteria for inclusion in Lake County’s investment attraction efforts in follow-up to board discussion of Feb. 24; consideration of proposed request for proposals for commercial and resort investor attraction; and consideration of staff recommendation for other economic development advisory services.
Non-timed items:
– Discussion/consideration of criteria and mechanism for accessing funds for road improvements in communities requiring subsidization of small area benefit zones.
– Discussion/consideration of request that the board recommend the Regional Council of Rural Counties (RCRC), amend the proposed 2009/2010 policy language to require conventional and
organic farmers who do not use genetically engineered seeds to undergo lab testing prior to being able to label their products/produce as “GE-Free.”
– Consideration of proposed agreement between the county of Lake and Remi Vista Inc. for placement of children in the residential treatment program in the amount of $30,000 (costs to be paid by Medi-Cal/early and periodic screening, diagnosis and treatment funding).
– Consideration of proposed amendment five to agreement between the county of Lake and Pavement Engineering Inc. for engineering services for design of rehabilitation improvements in Downtown Upper Lake (an increase of $34,210).
– An ordinance amending Chapter 3 of the Lake County Code providing for the abatement of unmanaged, neglected and abandoned pear and apple trees. Second reading; advanced from March 10.
– An ordinance establishing a fee schedule for outpatient substance abuse counseling as established by the state of California’s Drug Medi-Cal (DMC) reimbursement rates. Second reading; advanced from March 10.
The board also will have a closed session with labor negotiators.
E-mail Elizabeth Larson at
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