April 10, 2002 Report # 7 - A new goal - Response to EE/CA and Alternative 2C

A NEW GOAL

During the past several months the EPA goal for the Elizabeth Mine has been to eliminate the pollution sources to the maximum degree possible and to then provide "passive" treatment for the remaining contaminated water. The latter goal has led to ever increasing complexity and cost for the treatment system, and the latest proposal, in my opinion, will not even function properly on a year round basis here in Vermont. I think it is time to step back and redefine our goals, and at the same time accommodate as much as possible of the "compromise" proposals put forward by John Freitag and others.

The presently proposed treatment systems are expensive to build and maintain and operate, and their presence on the site will limit public access and recreational potential. The SRBÕs and SAPÕs (or treatment pools, as termed by John Freitag ), and likely the rest of the treatment systems, would have to be fenced to restrict public access. There would be continued truck traffic for the foreseeable future for the operation and maintenance activities. All this will reduce the potential for beneficial uses.

I believe our new goal should be a truly "passive" Elizabeth Mine site, without any treatment at all. This may not be possible, but should be the first priority of the forthcoming field investigations and design. It is clear that complete removal of TP3 would eliminate the treatment requirements for that portion of the site. However, it is also possible that a thorough site investigation could reveal portions of the area that would not contribute to pollution and it is possible that those portions could remain. However, it is likely that construction costs would increase significantly if preservation of isolated sites were included.

Eliminating treatment for TP1 is actually the more difficult goal. It is clear that without an impermeable cover on top of TP1 (to cut off infiltration of rainfall and snowmelt) it will continue to leak contaminated seepage, possibly forever, and require complex treatment forever. A cover on TP1, is therefore essential. With a proper cover in place the tailings will drain after a number of years, and any seepage will then be essentially groundwater. It seems possible, that this groundwater will be "clean" since it flows along the base of the tailings pile and does not come into contact with the contaminated material. If that is the case, then a treatment system would not be required for this groundwater. It is possible that the present seepage from TP1 diminishes to just this groundwater component during late winter/early spring. Sampling of the seepage at that time should reveal the water characteristics. If it is truly "clean" water then a long term treatment system would not be required. It might still be desirable to install a small simple wetland to catch any eroding sediments, but this wetland could have open water zones to attract birds and become a desirable part of the future site.

This approach, would however, require a "compromise" by the EPA and the State of Vermont. Even after TP1 is capped, it will continue to drain for a number of years and this seepage will not meet water quality standards at least until the only source is groundwater. The condition would be no worse (actually much better since TP3 would be gone) than present and would improve each year until drainage is complete and groundwater is the only seepage. The present condition has existed for at least 50 years, it does not seem too much to ask the regulatory agencies for a variance for another 20 years or so to allow the site to clean itself. During that period there would be a continuous improvement in water quality.

If, however, further investigation shows the groundwater to be unacceptably contaminated then a more complex treatment system would be necessary. In my opinion, the EPA has still to propose a viable system for our climate. In addition to the "treatment pools" IÕm afraid there will also be a large storage pond for winter storage of the flow and only summer time treatment.

Sherwood C. Reed, P.E.
Principal, E.E.C.

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