Water district expects $1 million in gold from Meadow Vista mercury removal
The Nevada Irrigation District is moving ahead on the possible acquisition of $595,000 in special equipment from a Canadian company to remove sediment and Gold Rush-era mercury from the Bear River watershed.
An official for the district added that a bonus for the district is expected to be an estimated $1 million in gold also coming out of the sediment that will help defray expenditures of $9 million over three years.
The equipment will be acquired on a lease-to-own basis from the Pegasus Earth Sensing Corp. for $12,650 a month – or a total purchase price of $595,000. The Alberta business will provide setup and startup services, staff training and technical support. The equipment could arrive as early as June.
“This project is the first of its kind in our region,” Irrigation District Director John Drew said. “We should all be proud that NID has taken the lead on a project like this.”
Tim Crouch, district assistant general manager, said the need continues to remove sediment that is washing down the Bear River and taking up valuable water-storage space in Rollins and Combie reservoirs.
Traditional dredging, however, stirs up methyl mercury buried in river bottoms. If disturbed, it can be ingested and absorbed into a complex food chain not only along rivers but throughout the Sacramento-Bay delta system, Crough said. Mercury is one of the lingering negative legacies of the Gold Rush, when miners used it to separate gold from dirt and gravel.
The mercury removal would take place on land now leased from the district at Lake Combie in Meadow Vista by Green Vista Holdings, a partnership that includes Teichert Aggregates.
Crough said the equipment would be tested over two to three years to see if it is what the district wants. Early tests estimate that 75 pounds of mercury could be extracted during the project. Because the equipment and process is new, Crough said much of the costs will be related to scientific testing and not to the actual extraction and sediment removal.
The property in Meadow Vista was formerly occupied by the Chevreaux Aggregates plant, which dredged and cleared sediment for use in its products through 2002.
While the sediment clearing has stopped, materials are still flowing downstream into Lake Combie, Crough said. One estimate indicates 200,000 tons of raw material in Lake Combie, he said.
The $9 million cost would be spread over three to five years, with the district not moving forward without funding it is hoping to get from the state and federal government.
“Removing sediment is a perpetual process,” Crough said. “It took 150 years to come down here and there’s a whole lot more upstream.”