Taku Inlet Site Testing
Taku Description and History
- Sunny Cove and Grizzly Bar are located on the intertidal shoreline of Taku Inlet.
- Historical mining operations and current discharges from the Tulsequah Chief, Big Bull, and New Polaris mines upstream are known to have discharged metals- laden mine wastes into the Tulsequah River.
- These mines include direct discharge of aluminum, arsenic, copper, lead, and zinc into the Tulsequah River and elevated concentrations of arsenic, copper, and selenium in fish tissue (Ridolfi, 2012).
- Both Sunny Cove and Grizzly Bar are located near traditional fish and shellfish resource areas used by tribal members for subsistence purpos No previous site assessment work has been conducted at either location.
Sunny Cove and Grizzly Bar Site Sampling
- Site sampling was conducted at Sunny Cove and Grizzly Bar in August 2014.
- At Sunny Cove, a total of 4 intertidal sediment samples were collected and analyzed.
- At Grizzly Bar, a total of 14 intertidal sediment samples were collected and analyzed.
- The 18 sediment samples were analyzed for metals that included arsenic, cadmium, copper, lead, mercury, selenium, silver, and zinc.
Sunny Cove and Grizzly Bar Site Analytical Results
- Analytical results for both Sunny Cove and Grizzly Bar included detected concentrations of arsenic, copper, and zinc.
- Although detected, the concentrations are in the typical range for stream sediments found in the area surrounding both sites.
- It is unlikely the observed metal concentrations are related to mining activities in the upper Taku River basin.
- It is also unlikely that tribal subsistence and cultural uses at these sites would result in significantly greater exposure risks than at other sites of the DIA territory.
Previous Sampling on the Taku
Hydrology and Glacier-Lake Outburst Floods (1987–2004) and Water Quality (1998–2003) of the Taku River
Can get a copy of the Report at:
The U.S. Geological Survey in cooperation with Douglas Indian Association, Alaska Department of Environmental Conservation, and the U.S. Environmental Protection Agency conducted a water-quality and flood- hydrology study of the Taku River. Water-quality sampling of the Taku River from 1998 through 2003 established a baseline for assessing potential effects of future mining operations on water quality.
The author gratefully acknowledges the assistance of Douglas Dobyns of the DIA for his help with fieldwork and logistics throughout the duration of the study.