The U.S. Forest Service is taking public comments about the agency’s proposal to spend about $1.2 million to deal with nine abandoned gold mines near Granite that have tailings and other waste rock contaminated with arsenic, lead and other potentially harmful elements.

The mines are all on public land.

The mines are near Granite Creek, a major tributary of the North Fork John Day River. The mines are the Monumental, Cap Martin, Tillicum, Sheridan, Golden Fraction, Central, and Granite Creek No. 5, 6 and 7.

A 30-day public comment period started April 2.

Forest Service officials will consider public comments before making a final decision about what to do with the mines, which are five to eight miles north of Granite.

The Forest Service hired Terraphase Engineering Inc. of Portland to assess the mines and suggest options for dealing with contaminated rock and soil.

The Forest Service is proposing four methods, depending on the situation at each mine:

• No action.

• Contain waste rock at the mine, piling it and covering it with uncontaminated soil from the site.

• Excavate contaminated rock and dispose of it at the mine.

• Excavate contaminated rock and dispose of it at a landfill.

The methods proposed depend mainly on the arsenic concentration in waste rock at each mine.

Some mines had arsenic levels below levels that are considered a public health hazard, according to the engineering firm’s report.

The report estimates the cost of all proposed work at $1.2 million.

According to the engineering report, mining in the area started in the 1860s and continued until World War II. In the first phase of mining, up to around 1890, most work was hand-dredging and placer mining, replaced by lode mining — digging shafts and tunnels and using chemicals to extract gold from ore.

In 2002 the Forest Service studied mines in the Granite Creek area, noting that two fish species protected by the federal Endangered Species List have been found in the Granite Creek watershed — bull trout and mid-Columbia steelhead.

According to a 2006 study, the highest concentrations of arsenic were at the Monumental and Tillicum mines.

The 2024 Terraphase Engineering report notes that arsenic can be concentrated due to amounts in the rock at the mine sites, and as a result of ore processing.

The report states that water samples from Granite Creek showed levels of arsenic and other metals “generally below ecological screening levels, suggesting that the relative contribution of flow from mine-related springs and seeps is not significant.”

The report recommends the Monumental Mine as the highest priority, and states that “arsenic is the only contributor for human health risk.”

Because the Monumental Mine is next to and visible from a road — 7345 — and has historical interest, that site is most likely to attract visitors, according to the report.

The full report is available online at https://tinyurl.com/mrxy65pm.

Written comments can be submitted by e-mail to: Mario A. Isaias-Vera, USFS On-Scene Coordinator, mario.isaias-vera@usda.gov; or to Andrew Schamber, USFS Regional Environmental Engineer Program Manager, andrew.schamber@usda.gov.