Mercury poses no threat to Carson River recreation

Although the federal government has been investigating the Carson River watershed for mercury contamination for decades, there is no current risk to recreationalists, a U.S. Environmental Protection Agency official said last week in Carson City.

“The big key theme, though, to note here is there are no major risks from recreational use of the land or water,” said Mohamed Ibrahim, a project manager from EPA’s Region 9. “That includes swimming and even incidental ingestion of the water if you’re swimming.”

However, eating fish from the Carson River Mercury Superfund Site, which stretches from the Mexican Dam in Carson City to the Stillwater National Wildlife Refuge in Churchill County, has been identified as a risk, Ibrahim said.

Ibrahim presented a history of the Superfund site, which was put on the National Priorities List in 1990. The mercury contamination stems from 19th century mining of the Comstock Lode. The EPA estimates that historic mining activity released 14 million pounds of mercury into the environment. The Superfund site encompasses around 330 square miles and five counties and has been divided into two Operable Units or OUs.

OU1 is comprised of old mining sites and tailings around Virginia City and Dayton, and OU2 is made up of the Carson River and its tributaries. OU1 is already in the cleanup phase, Ibrahim pointed out, while OU2 is still in the investigative and planning phases. Part of cleanup efforts include long-term soil sampling. The action level for mercury, he said, is 80 milligrams per kilogram in the soil.

Sampling soils around homes is voluntary, Ibrahim explained, and comes at no cost to the homeowner. Cleanup is also free, he said. In Carson City, seven homes in the Empire Ranch area in east Carson were voluntarily tested in November 2023 with results “well below” action levels, according to the EPA.

Resident Anna Winston was one of those homeowners. She told the Nevada News Group she was delighted the results were below action level but still wanted more testing done at the Empire Ranch Golf Course. However, David Friedman of the Nevada Division of Environmental Protection told the Appeal the Morgan Mill River Access area was investigated and remediated in the past, and there are no present-day risks.

Carson City supervisors Stacey Giomi and Lisa Schuette, who also sit on the board of the Carson Water Subconservancy District, worried about conflicts between FEMA and the EPA in flood events.

“If there’s a disaster declaration within the Superfund area, then FEMA disaster mitigation funds are not eligible to be used by a county to mitigate the damage done by the disaster because of the Superfund declaration,” Giomi said. “That’s a real problem, and it’s already been a problem for at least one county. I’m just wondering what efforts EPA and FEMA are working on to prevent that from happening in the future.”

“Yes, we are definitely looking into that. We are definitely aware of that,” Ibrahim responded, adding the EPA is trying to work with FEMA to clarify and resolve that issue.

“Well, I hope you communicate to your team and those above you that it is a real concern for us and our citizens because we stand to spend local money to mitigate problems that, you know, everyone else is able to get federal funds for,” Giomi said.

The EPA also proposed an interim remedy for OU2 including required sediment sampling before any development along the river. That would include bank stabilization projects, according to Ibrahim.

Schuette expressed hope federal agencies would work together and make it easier for the city to manage its portion of the river and mitigate problems.

“If we are wanting to fix this problem, we have to have the tools to do that,” she said. “And you don’t wait until the problem is huge to fix it, right? We try to fix it as we go along or at least reduce the effects of it.”