Beatson Mine

Site Narrative

Site History

The former Beatson Mine is located on the west side near the north end of Latouche Island in Prince William Sound. The Beatson-Bonanza claims were discovered by the Beatson Copper Company in 1897, and production of a copper sulfide ore at the Beatson Mine began in 1904. The "Alaska Syndicate" (J.P. Morgan and the Guggenheim family) purchased the mine in 1907, and then, in 1910, the mine was purchased by the Kennecott Copper Corporation, later renamed the Kennecott Utah Copper Corporation in 1989, when Minaska, Inc. (a subsidiary in the Rio Tinto group of companies) purchased certain assets, including the mineral rights to the Beatson Mine.  At its peak, in 1917-1918, there were about 300 people working at the Beatson Mine and about 4,000 people living on Latouche Island. The mine closed in 1930, reportedly due to low copper prices and little remaining high quality ore. Total copper production from the mine is reported as 182,600,000 pounds.

The Kennecott Copper Corporation, then owned by British Petroleum, owned the Beatson Mine property until 1962 when they sold the surface rights to James Sumpter. The mine-related structures were demolished in the 1960s-early 1970s. James Sumpter, operating as Latouche Island Development Corporation, owned the land until 1976 when he sold it to Basil and Elizabeth Bolstridge and Alfred and Agnes Derkerverkian. In 1978, the property was sold to Donald Marino, operating as Rare Earth, Inc. Mr. Marino subdivided the property, built roads and an airstrip using waste rock, and began selling parcels for residential or recreational use. The State of Alaska owns the intertidal lands. The land on Latouche Island outside of the former mining claims area is owned by the Chugach Alaska Corporation.

In 2013, the Alaska Department of Environmental Conservation (DEC) learned that potential contamination was present at the former Beatson Mine property. DEC researched the mine history and identified Minaska, Inc. as a responsible part of the former mine site.  Rio Tinto has been investigating possible environmental impacts at the site in 2016. Over the past several years, Rio Tinto has purchased many of the lots in the area impacted by the former mine; however, some have been retained by private owners.

Past Environmental History and Sampling

The principal ore body consists of chalcopyrite (copper-iron sulfide), pyrrhotite, and pyrite (both iron sulfides) scattered through the altered country rock and in small veinlets associated with quartz. Copper was found at 5-10% in small loads of ore. The surface oxidizing of the iron sulfide (pyrite and pyrrhotite) released small quantity of sulfuric acid (H2SO4). This process, due to weathering, is increased by the former mining activities, which may increase the acidity of surrounding waters and soil. Crushing of the host rock increases the surface exposed to weathering and subsequently the rate of acid formation. Acid mine drainage is visible throughout the area and consists of yellow and orange precipitates in the surface water.

Rio Tinto conducted work at the Beatson Mine in 2016, and annually in 2018-2021. These activities included site reconnaissance, sample collection (soil, waste rock, surface water, groundwater, sediment, and biological tissue), and ecological investigation. Conducting these kinds of activities over several years is typical for large, complex projects such as this one. Some of the broad conclusions from the report include:

• Soils containing the highest concentrations of metals were found at the disturbed areas near some of the waste rock piles, from the Blackbird Mine road, and at the Beatson Mine main area. Soil containing petroleum hydrocarbons was found near the aboveground tank and associated buried pipelines, the landing strip, and in the main Beatson Mine area.
• The site is located in a highly-mineralized area and background reference samples of soil and sediment contained naturally-occurring elevated concentrations of metals.
• Waste rock was found in waste rock piles across the site as well as on roads. An updated estimate of the volume of waste rock on site is around 265,000 cubic yards.
• Groundwater near the Blackbird Mine and on the northern shoreline contained elevated concentrations of metals. Installation of monitoring wells is difficult due to the terrain.
• Surface water sample results showed metals concentrations that exceed Alaska Water Quality Standards for aquatic life at many locations, while sample results at four locations exceeded Alaska Water Quality standards for drinking water (for copper only).
• Marine and freshwater stream sediment contained metals concentrations above screening levels for protection of plants and animals.

Rio Tinto has completed a fairly thorough investigation of this site and some additional information is needed. Further sampling is needed to determine if there are trends and seasonal variation in metals concentrations in surface water and groundwater.

Current Environmental Investigation Activities

Rio Tinto continues to conduct annual site characterization activities to further refine their understanding of the site and assist in determining how to best clean it up. Site characterization reports are included on the DEC Contaminated Sites Database. Rio Tinto is also working with other DEC programs to make sure that the cleanup will be in compliance with all State regulations.   

In 2023, DEC and Rio Tinto will continue to discuss how to address the submerged tailings that were placed in the ocean via a flume by the former operator. Rio Tinto will submit a Screening Level Risk Assessment Work Plan for DEC comments. Following resolution of the comments and approval of the work plan, Rio Tinto will conduct the Risk Assessment to evaluate risk exposure pathways and develop cleanup levels. Rio Tinto will also submit a Site Characterization Report detailing their field activities from 2022. DEC will review and comment on the report and discuss how to resolve the comments. Finally, Rio Tinto plans to conduct additional field activities in Summer 2023.

Rio Tinto is engaging with Latouche Island subdivision property owners and other interested parties on the status of its field activities and site characterization efforts.