Geochemical Characteristics of TP3 Mine Wastes at the Elizabeth Copper Mine Superfund Site, Orange County, Vermont

Abstract

Remediation of the Elizabeth mine Superfund site in the Vermont copper belt poses challenges for balancing environmental restoration goals with issues of historic preservation while adopting cost-effective strategies for site cleanup and long-term maintenance. The waste-rock pile known as TP3, at the headwaters of Copperas Brook, is especially noteworthy in this regard because it is the worst source of surface- and ground-water contamination identified to date, while also being the area of greatest historical significance. The U.S. Geological Survey (USGS) conducted a study of the historic mine-waste piles known as TP3 at the Elizabeth mine Superfund site near South Strafford, Orange County, VT. TP3 is a 12.3-acre (49,780 m2) subarea of the Elizabeth mine site. It is a focus area for historic preservation because it encompasses an early 19th century copperas works as well as waste from late 19th- and 20th century copper mining (Kierstead, 2001). Surface runoff and seeps from TP3 form the headwaters of Copperas Brook. The stream flows down a valley onto flotation tailings from 20th century copper mining operations and enters the West Branch of the Ompompanoosuc River approximately 1 kilometer downstream from the mine site. Shallow drinking water wells down gradient from TP3 exceed drinking water standards for copper and cadmium (Hathaway and others, 2001). The Elizabeth mine was listed as a Superfund site in 2001, mainly because of impacts of acid-mine drainage on the Ompompanoosuc River.