The Argonaut Tailings Dam will receive improvements to remedy the threat of toxic material flowing into Jackson.


The Jackson City Council received an update on the effort to reinforce the Argonaut Tailing Dam as new construction is starting at the site.

The 100-year-old concrete dam holds back tons of mine tailings, the remains of ore after it has been processed that contain arsenic and other heavy metals. Should the dam fail, the potentially toxic material could flow downhill into downtown Jackson. Concerns over the structural integrity of the dam have already lead a number of state and federal agencies to make improvements at the site; what is now starting is the reinforcement of the dam itself.

The dam will be reinforced with fresh concrete filling in the existing structure and then a large earthen embankment will be placed along the front of the dam. Preliminary work on the site has already begun, and the construction project is expected to take six months. There will be intermittent road closures and traffic controls on Sutter Street and Argonaut Drive during construction. The state will take responsibility to maintain the site in the future, and there are future plans to further improve drainage in the area, if additional funds are obtained. The Federal EPA will also be conducting ground water and soil testing in the area for any sign of arsenic contamination spreading.