Groundwater Investigation: Elusive elements

By EVE BYRON Independent Record | Posted: Sunday, November 21

As the yard removal portion of the Asarco cleanup effort in East Helena is winding down, work on dealing with the arsenic and selenium plumes is just gearing up.

While the Environmental Protection Agency has known for a decade that the underground arsenic plume is flowing from the former lead-smelting plant toward one of East Helena’s city water wells and individual wells in the Helena valley, it hasn’t come up with a solution for dealing with it. Muddying the arsenic-plume situation was the discovery in 2006 of a plume of selenium in the groundwater that’s moving in the same general direction.

Asarco led the plume monitoring and analyzing effort in conjunction with the EPA, with thousands of water samples analyzed. But now that Asarco no longer is in the picture due to a year-old bankruptcy agreement, the EPA and the newly formed Montana Environmental Custodial Trust have brought in a trio of new faces to figure out what’s been done in the past, where data is missing, and how to move forward with a permanent solution that will protect the community’s health.

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