The Latest News on Cleanup at Red Devil Mine site
November 7, 2013
|Power plant, shaft house and rotary furnace installation, Red Devil Mine. Kuskokwim Region, Georgetown District, Alaska. September 19, 1943 — at Red Devil, AK.|
Last week, GTC received an update on the cleanup of the abandoned mercury mine located at Red Devil, Red Devil Mine (RDM). The information we got was as follows:
- At this point, the remedial investigation (RI) is almost final.
- The draft feasibility study (FS) has been reviewed – and lays out various remedies for cleanup to address contamination
- BLM is working on a study, trying to develop a mixture to add to the tailings on site
- BLM is planning a removal action for next summer. It will pull contamination back from creek
- BLM will be meeting with the public next spring to talk about that plan.
The Cleanup Process under CERCLA
First it is important to understand that the cleanup at RDM is being conducted under the CERCLA process. The basic outline of events are as follows:
A Remedial Investigation(RI) is conducted to outline what is taking place at the site of interest. Studies are conducted and the problem is identified.
Next a Feasibility Study(FS) is done, identifying 4 possible ways to clean up the RDM site
Once these are complete, a Proposed Plan is issued to the public, basically describing the RI/FS process and outcomes in an understandable manner.
Public comment and community meetings take place following the proposed plan, and once comments are taken into consideration along with all of the other findings,
A Record of Decision (ROD) is issued with the final decision on how to proceed with cleanup at RDM.
So where are we now in this process?
The draft FS was sent from BLM to EPA in April. BLM, EPA and DEC will be conducting meetings soon to discuss comments on that document. Following that, the Final FS will be issued, and that is expected out next summer.
BLM already has a contractor on board to do the proposed plan and Record of Decision (ROD) following the issuance of the FS. Public commenting and community meetings are expected to occur in Feb/March of 2015, prior to the issuance of the ROD.
In the Feasibility Study, there are 4 different alternatives of dealing with the site as a whole that they will need to decide between:
- No action
- Leave tailings where they are, and put up signs and fences around the site, thus reducing the risk of exposure to wildlife and human populations
- Remove the tailings in and next to creek where water leaches tailings – build a repository up above the creek where there is a flat area, move the tailings there and cover it with something to prevent leaching
- Excavate the tailings the same as #3 but barge it out instead of moving it to another location on site.
What about that Mixture they'll add to the site?
As part of alternative #3, there are tailings on site that have high concentrations of Mercury, Antimony and Arsenic. There is a procedure called TCLP (toxicity characteristic leaching procedure) which is designed for municipal landfills that can be applied to the tailings – where you combine a certain chemical with the tailings, let it sit and then filter off the solids and check the solution for the concentration of metals. If it is at a certain level, it is said to have a “toxicity characteristic”. This would give it special regulatory status under the Resource Conservation and Recovery Act (RCRA), where it would need to be handled and disposed of as hazardous waste.
This was done to the tailings at RDM and the tailings to the south side of the creek where not a lot of stuff is growing, failed for Arsenic. On the north side of the creek, no samples failed. The tailings that failed this test are now considered hazardous waste and must be handled under RCRA.
There are two kinds of waste under RCRA – listed materials (where RCRA always applies) and materials that display characteristics at a certain level (RCRA applies unless treated to a point where they no longer display these characteristics). The tailings that failed Arsenic tests at RDM are the second of these kinds of waste.
So since some of the tailings are now considered hazardous waste, BLM is doing a treatability study as part of the FS, which is where the “mixture” referred to at the beginning of this article comes in.
BLM took samples of that material last summer, and are looking at solidifying or encapsulating it with a cement type mixture then re-running for TCLP. If it passes, it makes the tailings easier to handle and they wouldn’t need to be disposed of as hazardous waste or given special status under RCRA. If alternative #3 is the route that is chosen, and this proves to be a good way to go, then this is what would be done to all of those tailings.
EARLY ACTION is another term that comes into play when talking about RDM Cleanup.
While working on the site wide strategy, if there is an obvious part of the problem that you can do something about you are allowed to say – here’s the problem right here, we don’t have to wait to do something about this specific issue. This is called an early or interim action. In this case the immediate problem is that the tailings are moving into the creek out into the Kuskokwim River and they need to do something to stop that from happening.
So next summer they plan to move tailings away from the creek. They are focused on creek and material next to creek to prevent movement to the river. Early action would not move tailings OFF SITE , just move them away from the creek.
In order to complete the early action, BLM needs to complete a risk assessment, and develop a document called an engineering evaluation cost analysis (EECA) – which is like a mini RI/FS focused just on that action.
BLM is developing an EECA now and in January, plans to talk with communities about EECA and ethe arly action plan.
Mike McCrum will be giving a presentation of this material at AFE this February in Anchorage. Keep your eye out for more information as it becomes available.