Site Report: Perseverance Mill
| Site Name: | Perseverance Mill |
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| Address: | Perseverance Mine Trail, Perseverance Valley, Juneau, AK 99801 |
| File Number: | 1513.38.012 |
| Hazard ID: | 403 |
| Status: | Active |
| Staff: | Brittani Mack, 9072697558 brittani.mack@alaska.gov |
| Latitude: | 58.307060 |
| Longitude: | -134.335100 |
| Horizontal Datum: | NAD83 |
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We make every effort to ensure the data presented here is accurate based on the best available information currently on file with DEC. It is therefore subject to change as new information becomes available. We recommend contacting the assigned project staff prior to making decisions based on this information.
Problems/Comments
Tailings disposal site spanning about one acre that received ore processing milling residuals in the early 1900s. Elevated levels of arsenic, lead, zinc, and mercury are present in the tailings piles. The disposal site is at the end of a popular hiking trail and at the headwaters of Gold Creek, one of two sources of drinking water for the City and Borough of Juneau. In a study by the landowner in 1988, the tailings pile material was asserted to be hazardous but stable. Chemical analysis of soil and water samples showed that contamination is obviously too toxic to allow plant succession in the disposal area; was not migrating to surface or groundwater above maximum contaminant levels (MCLs). Lead up to 12,500 mg/kg, arsenic 2,240 mg/kg, mercury 16 mg/kg, and zinc 657 mg/kg in surficial soils. Stream sediment approximately two miles downstream of site showed lead at 404 ppm, arsenic 45.8 ppm, zinc 177 ppm, and mercury 17.8 ppm. No surface water or groundwater contamination above drinking water standards by heavy metals has thus far have been detected. 2016: The ADEC worked with the City and Borough of Juneau to place warning signs on site until such time that a clean up can occur. Warning signs currently in place. EPA SEMS: AKD980975106
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 1/1/1984 | Update or Other Action | (Old R:Base Action Code = SI - Site Investigation). Investigation by TetraTech. | Former Staff |
| 7/1/1986 | Site Characterization Report Approved | (Old R:Base Action Code = SI - Site Investigation). Tryck, Nyman and Hayes, SAIC, and Shannon and Wilson, Inc. "Suspected Uncontrolled Hazardous Waste Site Inspections, Perseverance Mill, Juneau, Alaska." Sampling of soil, stream sediment and surface and groundwater. Water showed trace levels of contamination by zinc (below drinking water standards). Surficial soils and stream sediments showed heavy metal contamination. | Former Staff |
| 9/1/1987 | Update or Other Action | "Suspected Uncontrolled Waste Site Inspections, Perseverance Mill" prepared by Shannon and Wilson, Inc. | Former Staff |
| 1/4/1989 | Update or Other Action | (Old R:Base Action Code = SI - Site Investigation). Performed by Versar, Inc. for City/Borough of Juneau and Alaska Electric Light and Power. Concluded noticeable environmental impact only in area of tailings disposal. Chemical analyses showed Gold Creek not impacted by presence of tailings. | Former Staff |
| 4/27/1990 | Site Ranked Using the AHRM | Initial ranking. | Former Staff |
| 6/1/1991 | Update or Other Action | "Draft Site Inspection Report for Treadwell Mine" received. Prepared by Ecology and Environment, Inc. | Former Staff |
| 8/26/1993 | Site Added to Database | Elevated levels of arsenic, lead, zinc, and mercury are present in tailings. | Former Staff |
| 11/17/1995 | Site Ranked Using the AHRM | This site was re-ranked. Air Exposure Index Value was changed and Quantity Value was changed. | Sally Schlichting |
| 7/1/2005 | Update or Other Action | Project Management changed to Wanstall | Bruce Wanstall |
| 7/15/2008 | Exposure Tracking Model Ranking | Initial ranking with ETM completed based on historical data-set. Current exposure risk for the surface soil ingestion and wild foods pathways for about 90 days in the summer season. The future exposure risk is year-round for the surface and ground water pathways in the Gold Creek watershed. Monitoring data for current status is requested from CBJ Lands Department. | Bruce Wanstall |
| 10/11/2012 | Site Visit | Site visit with staff (Wanstall & Brown). Noticed no signs were in place. | Erik Norberg |
| 9/11/2013 | Update or Other Action | Staff changed from Erik Norberg to Denise Elston. | Kristin Thompson |
| 3/6/2015 | Site Visit | Staff Schlichting and Duncan visited the site and observed the tailings area. There was less than an inch of snow and some ice. There was a black lichen? growing on the tailings and stunted trees and vegetation were observed. No warning signs are in place at this time. | Danielle Duncan |
| 8/26/2015 | Update or Other Action | Requested that signs be placed warning visitors of metals contamination in the area. Sent certified this date. | Danielle Duncan |
| 9/29/2015 | Update or Other Action | CBJ Streets is going to make and install the sign(s). | Danielle Duncan |
| 2/16/2016 | Update or Other Action | Per the City, they are planning on placing the warning sign as soon as the ground has thawed and there is no snow. | Danielle Duncan |
| 5/29/2016 | Update or Other Action | Rec'd pictures of the warning signs - should be effective in warning the public. | Danielle Duncan |
Contaminant Information
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Control Type
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Requirements
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No associated sites were found.