Fate of Androscoggin River Floodplain Mercury from the Chlor-Alkali Facility Superfund Site, Berlin, NH

Devon Renock, Ph.D.
Brian P. Jackson, Ph.D.
Carl E. Renshaw, Ph.D.

The former Chlor-Alkali Facility in Berlin, New Hampshire was listed on the National Priorities (Superfund) list in 2005 for its mercury discharges into the Androscoggin River. Despite remediation efforts, there are still high levels of mercury in the river floodplain and while floodplains are generally effective at absorbing and storing chemicals, certain natural processes can release mercury stored in the soil. For example, soil saturation through rainfall changes the soil conditions, allowing mercury in the soil to be converted into forms that can move freely through the environment. Climate predictions for New Hampshire suggest an increase in regional rainfall that could promote mercury conversion, releasing mercury stored in the soil to enter river and downstream surface waters. In our pilot study, we are examining the interactions between the floodplain's seasonal patterns and the organisms and chemicals in its soils to understand how mercury is converted to its more mobile form and assess the likelihood of mercury releases into the river channel and atmosphere in the future.