Acidic, metal-rich waters from mines flow into Prince William Sound
This story entered on 18th Oct, 2004 07:00:00 AM PST

Groundwater and surface water associated with the former copper mines on Latouche Island, Prince William Sound, have been documented to contain elevated levels of acid and dissolved metals, which result from weathering of copper sulfide tailings. However, determining the presence of these acids and metals in the nearby marine environment, by analysis of seawater, has been difficult to establish due to their rapid dispersal into the Sound's bays and fords.

A NURP-sponsored study utilized a novel approach to determine whether metals leached from Prince William Sound mines flow to the marine environment. The study results indicate that plumes of acidic, metal-rich groundwater originating from mines are indeed discharging into the intertidal zone of Prince William Sound.

Rather than studying samples of seawater, Drs. Randy Koski and Pat Shanks of the USGS and Dr. Lee Ann Munk from the University of Alaska Anchorage analyzed the gravel and water of subsurface beach sands in the zone of mixing between groundwater and seawater. The researchers, funded by NURP's West Coast and Polar Regions Center, concluded that acidic water containing elevated levels of iron, barium, lead, mercury, thallium, zinc and copper entered the bay.

Establishing that mines contribute acidic water containing dissolved metals to Prince William Sound is new scientific information that can be useful to coastal managers. While it is known that elevated levels of some metals can be toxic, the impact of acidic metal-rich water on the ecology of Prince William Sound is largely unknown. Building upon the findings of this study, future research may investigate the fate of dissolved metals in the Prince William Sound ecosystem.

Contact information
Name: Jennifer Reynolds
Tel: (907) 474-5871
jreynolds@ims.uaf.edu