NID OK’s contracts on mercury removal project at Combie Reservoir |

NID OK’s contracts on mercury removal project at Combie Reservoir

The Nevada Irrigation District board of directors gave the go-ahead to a total $6.6 million in contracts for the Combie Sediment and Mercury Removal Project on Wednesday.

The project is expected to cost $7.4 million, with the bulk of that funding — $5.5 million — coming from the Department of Water Resources’ Riverine Stewardship Program. The project got under way in July of last year and will remove sediment from the reservoir, while extracting mercury using an innovative centrifuge technology. This pilot project is estimated to take three to four years to complete.

If the project demonstrates mercury can be effectively removed from river sediments, the process can be applied at other reservoirs throughout the Sierra Nevada, according to NID. NID has been testing the new technology that suctions sediment from waterways and funnels it into a centrifuge machine, which spins and cleans the sediment and removes 98 percent of mercury.

The district plans to remove and clean 150,000 cubic yards of sediment from the reservoir. Contracts that were approved were nearly $520,000 to Holdredge & Kull/NV5 for project management; $869,000 to the U.S. Geological Survey for collection and analysis of the sediment; and $4.6 million to Great Lakes Environmental & Infrastructure and Teichert Aggregates, for the actual removal of the sediment.

Initially the district planned to sell the sediment, but staff has been told it is not marketable currently because it is not in demand. The sediment is currently being cleaned of mercury and clay and will be stored until they can sell it sometime in the future.

NID will pay Teichert Aggregates $600,000 for long-term storage.

Contact reporter Liz Kellar at 530-477-4236 or by email at

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