Soil contamination south of Mammoth

usfssign.jpg(Forest Service Press Release)  Elevated Levels of Metals found at the Mill City Stamp Mill Bishop, Calif., April 14, 2014

Elevated levels of mercury, lead, and arsenic have been detected during preliminary sampling of soils and historic mill tailings at the Mill City Stamp Mill, south of Old Mammoth and east of Twin Lakes.

In 2012, CalTrout received a grant from the Lahontan Regional Quality Control Board to monitor water quality in Mammoth Creek. Monitoring included mercury, manganese, and others. The study conducted by CalTrout in 2012-2013 showed elevated levels of mercury in Mammoth Creek and that concentrations were the highest near the Mill City Stamp Mill. Based on the CalTrout study, the US Forest Service conducted the preliminary site sampling near the Stamp Mill in 2013.

The US Forest Service preliminary sampling at the Stamp Mill showed elevated levels of mercury, lead and arsenic in the soil and historic mill tailings. The detected levels of arsenic, lead and mercury in the preliminary sampling indicate that there is a potential risk to site visitors and nearby residents. Additional sampling is required to fully delineate the nature and extent of contamination that may be present as a result of historic mining activities at the site.

The US Forest Service will be conducting a Site Investigation this spring and summer to determine the full nature and extent of contamination and to better assess the degree of risk to recreational visitors, nearby residents, and to the environment and what actions may be needed to mitigate these risks.

“While we do not know the nature or extent of mercury contamination, we want to share the information we currently have with residents and visitors to the area,” said Ed Armenta, Forest Supervisor.

For more about mercury and human health, visit #

17 Responses to Soil contamination south of Mammoth

  1. Tinner April 16, 2014 at 4:53 pm #

    Maybe the Forest Service keeps it confusing to keep us asking questions so they can keep their job…maybe.

  2. Dan Watson April 15, 2014 at 2:46 pm #

    The Mill City Tract is a group of old cabins on Forest Service land at the very west end of Old Mammoth. They are off of Old Mammoth Road near Fir Street, just west of the neighborhood known as the Bluffs.

    • Ken Warner April 16, 2014 at 8:53 pm #

      Thanks Chief Watson. I know exactly where those cabins are. I didn’t know what they were called.

      I was told that the mine up on Mineral Hill just West of those cabins collapsed in an earthquake in the late 1800’s and was then abandoned. But that may be just a story.

      “The Great Lone Pine earthquake was one of the largest earthquakes to hit California in recorded history.”

      I suppose that those tailings — which you can still see — have been polluting Mammoth Creek since then. I don’t have a complete history of that mine.

      • Explorer April 17, 2014 at 9:38 am #

        Ken, this is a good link to get information about those old mines. It tells what they were mining, and describes the underground workings of the majority of mines in Mono County.

        • Ken Warner April 17, 2014 at 11:51 am #

          Thanks. Having a little trouble focusing that site on Mammoth Lakes.

  3. Bert4 April 15, 2014 at 1:19 pm #

    I think that the Bishop byline indicates that the press release came from the Forest Supervisor’s Office in Bishop, not that the location of the heavy metal contamination is in Bishop. Some punctuation could’ve helped that.

  4. ferdinand lopez April 15, 2014 at 10:04 am #

    I cant wait to see if im gonna die from eating the “fresh trout”out of the lakes basin

  5. Ken Warner April 14, 2014 at 8:33 pm #

    I haven’t seen a lot of people hanging around there — if I understand where the problem is — and I’ve never seen anybody eating the tailings or the dirt or drinking Mammoth Creek water. But I’m not sure exactly where they found the problem.

    A rough map would help pinpoint the location.

    • Ross Orr April 15, 2014 at 12:32 pm #

      Hi Ken,

      Our company looks for arsenic issues created by historic mine tailings. We bioleach (use natural bacteria) the sulphides in the tailings that cause the acidic discharge. The discharge also solubilizes arsenic, lead etc that gets taken away with rain or snow melt. Is this a new problem or something that has been known about for some time. Are there a lot of old mine tailings in the area?


      Ross Orr
      BacTech Environmental

      • Benett Kessler April 15, 2014 at 1:02 pm #

        You should contact the Inyo National Forest.
        Benett Kessler

      • Ken Warner April 15, 2014 at 3:14 pm #

        Arsenic in the drinking water has been an ongoing problem. Not a lot of arsenic but some. One well had to be shut down by MCWD because of high arsenic levels a while back. Don’t know the status as of today.

        Yes, there are a lot of old mines. They’ve been inactive for so long it’s hard to identify the tailing piles from natural scree.

        Mammoth Community Water District (MCWD) would be the people to contact for water analysis issues.

  6. MK April 14, 2014 at 7:21 pm #

    Mill City in Bishop! ?

    Was that a typo?

    • Benett Kessler April 14, 2014 at 9:42 pm #

      No. It’s a location south and east of Old Mammoth, according to the Forest Service.

      • MK April 15, 2014 at 8:26 am #


        I am confused. The article says Bishop.

        I know of Mill City Stamp mile next to Coldwater Campground and the trail head to Duck pass.

        This is the water shed into Lake Mary and Mammoth Creek. This is just above the Town of Mammoth.

        I wonder if we have Cancer clusters above the norm here. I know many who have had some type of cancer.

        • Benett Kessler April 15, 2014 at 9:42 am #

          The Forest Service told me it’s east of Old Mammoth and south of Twin Lakes. That’s all I know.

          • Ken Warner April 15, 2014 at 11:14 am #

            Confusing location from the F.S. There used to be a stamp mill by the old gold mine by Coldwater Creek but the water wheel was moved to it’s present location in front of Snowcreek in 1902 — according to available information.


            There is another stamp mill just above some cabins just West and South of Old Mammoth. There’s an old flywheel there. Where the actual stamp mill was — I don’t know.


            Both sites have been there for over a hundred years. Whatever heavy metals we’ve ingested during that time is already a done deal.

          • SB April 15, 2014 at 3:24 pm #

            “at the Mill City Stamp Mill, south of Old Mammoth and east of Twin Lakes.”



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