March 20, 2009
With the removal this week of the concrete divider block, the last visible remains of the Milltown Dam are now gone. Next week, the breach of the cofferdam will lower the river two to three feet and allow the Clark Fork to be diverted into its future (and possibly one-time) channel at the base of the Milltown Bluff. (The photo above depicts divider block removal in the center, the cofferdam’s edge in the center-right side and the future river channel in the lower right corner.)
Envirocon also has been preparing for the breach of the spillway cofferdam by reducing berm’s size, by digging a downstream channel and by turning off the pumps to allow the area behind the old spillway to flood.
Elsewhere, the project continues to make headway. Thus far, more than 75 percent of the more than two million cubic yards of contaminated sediments have been removed and shipped, and the last load is expected to be hauled in October.
With the contaminated sediments excavated down to the original flood plain, Envirocon has begun to remove the infrastructure (such as haul roads) from the site. By May, it will begin pulling up the rail line spur.
For more on the latest cleanup news, see the EPA’s March 18 project update (PDF) as well as local media coverage from KPAX television and the Missoulian, March 17 and March 15.